diff --git a/Aws/S3/Error.hs b/Aws/S3/Error.hs
--- a/Aws/S3/Error.hs
+++ b/Aws/S3/Error.hs
@@ -8,9 +8,23 @@
 import           Data.Typeable
 import           Text.XML.Monad
 import qualified Control.Exception         as C
+import qualified Data.ByteString           as B
+import qualified Network.HTTP.Types        as HTTP
 
+type ErrorCode = String
+
 data S3Error
-    = S3XmlError { 
+    = S3Error {
+        s3StatusCode :: HTTP.Status
+      , s3ErrorCode :: ErrorCode -- Error/Code
+      , s3ErrorMessage :: String -- Error/Message
+      , s3ErrorResource :: Maybe String -- Error/Resource
+      , s3ErrorHostId :: Maybe String -- Error/HostId
+      , s3ErrorAccessKeyId :: Maybe String -- Error/AWSAccessKeyId
+      , s3ErrorStringToSign :: Maybe B.ByteString -- Error/StringToSignBytes (hexadecimal encoding)
+      , s3ErrorMetadata :: Maybe S3Metadata
+      }
+    | S3XmlError { 
         fromS3XmlError :: XmlError
       , s3XmlErrorMetadata :: Maybe S3Metadata
       }
@@ -26,5 +40,8 @@
     strMsg = fromXmlError . strMsg
 
 instance WithMetadata S3Error S3Metadata where
-    getMetadata = s3XmlErrorMetadata
-    setMetadata m a = a { s3XmlErrorMetadata = Just m }
+    getMetadata S3Error { s3ErrorMetadata = m } = m
+    getMetadata S3XmlError { s3XmlErrorMetadata = m } = m
+
+    setMetadata m a@S3Error{} = a { s3ErrorMetadata = Just m }
+    setMetadata m a@S3XmlError{} = a { s3XmlErrorMetadata = Just m }
diff --git a/Aws/S3/Query.hs b/Aws/S3/Query.hs
--- a/Aws/S3/Query.hs
+++ b/Aws/S3/Query.hs
@@ -14,11 +14,10 @@
 import           Data.Maybe
 import           Data.Monoid
 import           Data.Time
-import qualified Blaze.ByteString.Builder as Blaze
-import qualified Data.Ascii               as A
-import qualified Data.ByteString          as B
-import qualified Data.ByteString.Lazy     as L
-import qualified Network.HTTP.Types       as HTTP
+import qualified Data.Ascii           as A
+import qualified Data.ByteString      as B
+import qualified Data.ByteString.Lazy as L
+import qualified Network.HTTP.Types   as HTTP
 
 data S3Query
     = S3Query {
diff --git a/Aws/S3/Response.hs b/Aws/S3/Response.hs
--- a/Aws/S3/Response.hs
+++ b/Aws/S3/Response.hs
@@ -8,13 +8,17 @@
 import           Aws.S3.Metadata
 import           Aws.Util
 import           Control.Applicative
-import           Control.Exception
+import           Control.Monad.Compose.Class
+import           Data.Char
 import           Data.Maybe
-import qualified Data.Ascii              as A
-import qualified Data.ByteString         as B
-import qualified Data.Enumerator         as En
-import qualified Network.HTTP.Enumerator as HTTP
-import qualified Network.HTTP.Types      as HTTP
+import           Data.Word
+import           Text.XML.Monad
+import qualified Data.Ascii                  as A
+import qualified Data.ByteString             as B
+import qualified Data.Enumerator             as En
+import qualified Network.HTTP.Enumerator     as HTTPE
+import qualified Network.HTTP.Types          as HTTP
+import qualified Text.XML.Light              as XL
 
 data S3Response a
     = S3Response {
@@ -30,7 +34,9 @@
       let amzId2 = headerString "x-amz-id-2"
       let requestId = headerString "x-amz-request-id"
       
-      specific <- tryError $ s3ResponseIteratee status headers
+      specific <- tryError $ if status >= HTTP.status400
+                             then s3ErrorResponseIteratee status headers
+                             else s3ResponseIteratee status headers
       
       case specific of
         Left (err :: S3Error) -> En.throwError (setMetadata m err)
@@ -41,8 +47,48 @@
                                       , s3RequestId = requestId
                                       }
 
+s3ErrorResponseIteratee :: HTTP.Status -> HTTP.ResponseHeaders -> En.Iteratee B.ByteString IO a
+s3ErrorResponseIteratee status headers = xmlResponseIteratee (e <<< parseXmlResponse) status headers
+    where                 
+      e :: Xml S3Error XL.Element a
+      e = do
+        err <- e' <<< findElementNameUI "Error"
+        raise err
+      
+      e' = do
+        code <- strContent <<< findElementNameUI "Code"
+        message <- strContent <<< findElementNameUI "Message"
+        resource <- tryMaybe $ strContent <<< findElementNameUI "Resource"
+        hostId <- tryMaybe $ strContent <<< findElementNameUI "HostId"
+        accessKeyId <- tryMaybe $ strContent <<< findElementNameUI "AWSAccessKeyId"
+        stringToSignUnprocessed <- tryMaybe $ strContent <<< findElementNameUI "StringToSignBytes"
+        let stringToSign = B.pack <$> (sequence . map readHex2 . words =<< stringToSignUnprocessed)
+        
+        return S3Error { 
+                     s3StatusCode = status
+                   , s3ErrorCode = code
+                   , s3ErrorMessage = message
+                   , s3ErrorResource = resource
+                   , s3ErrorHostId = hostId
+                   , s3ErrorAccessKeyId = accessKeyId
+                   , s3ErrorStringToSign = stringToSign
+                   , s3ErrorMetadata = Nothing
+                   }
+
+      readHex2 :: [Char] -> Maybe Word8
+      readHex2 [c1,c2] = do
+        n1 <- readHex1 c1
+        n2 <- readHex1 c2
+        return . fromIntegral $ n1 * 16 + n2
+      readHex2 _ = Nothing
+      
+      readHex1 c | c >= '0' && c <= '9' = Just $ ord c - ord '0'
+                 | c >= 'A' && c <= 'F' = Just $ ord c - ord 'A' + 10
+                 | c >= 'a' && c <= 'f' = Just $ ord c - ord 'a' + 10
+      readHex1 _                        = Nothing
+
 class S3ResponseIteratee a where
     s3ResponseIteratee :: HTTP.Status -> HTTP.ResponseHeaders -> En.Iteratee B.ByteString IO a
 
-instance S3ResponseIteratee HTTP.Response where
-    s3ResponseIteratee = HTTP.lbsIter
+instance S3ResponseIteratee HTTPE.Response where
+    s3ResponseIteratee = HTTPE.lbsIter
diff --git a/Aws/Signature.hs b/Aws/Signature.hs
--- a/Aws/Signature.hs
+++ b/Aws/Signature.hs
@@ -5,12 +5,13 @@
 import           Aws.Credentials
 import           Aws.Query
 import           Data.Time
-import qualified Crypto.HMAC               as HMAC
-import qualified Crypto.Hash.SHA1          as SHA1
-import qualified Crypto.Hash.SHA256        as SHA256
-import qualified Data.ByteString           as B
-import qualified Data.ByteString.Base64    as Base64
-import qualified Data.Serialize            as Serialize
+import qualified Crypto.Classes         as Crypto
+import qualified Crypto.HMAC            as HMAC
+import qualified Crypto.Hash.SHA1       as SHA1
+import qualified Crypto.Hash.SHA256     as SHA256
+import qualified Data.ByteString        as B
+import qualified Data.ByteString.Base64 as Base64
+import qualified Data.Serialize         as Serialize
 
 data TimeInfo
     = Timestamp
@@ -64,5 +65,6 @@
       sig = case ah of
               HmacSHA1 -> computeSig (undefined :: SHA1.SHA1)
               HmacSHA256 -> computeSig (undefined :: SHA256.SHA256)
+      computeSig :: Crypto.Hash c d => d -> B.ByteString
       computeSig t = Serialize.encode (HMAC.hmac' key input `asTypeOf` t)
       key = HMAC.MacKey (secretAccessKey cr)
diff --git a/Aws/SimpleDb/Error.hs b/Aws/SimpleDb/Error.hs
--- a/Aws/SimpleDb/Error.hs
+++ b/Aws/SimpleDb/Error.hs
@@ -8,12 +8,13 @@
 import           Data.Typeable
 import           Text.XML.Monad
 import qualified Control.Exception         as C
+import qualified Network.HTTP.Types        as HTTP
 
 type ErrorCode = String
 
 data SdbError
     = SdbError {
-        sdbStatusCode :: Int
+        sdbStatusCode :: HTTP.Status
       , sdbErrorCode :: ErrorCode
       , sdbErrorMessage :: String
       , sdbErrorMetadata :: Maybe SdbMetadata
diff --git a/Aws/SimpleDb/Response.hs b/Aws/SimpleDb/Response.hs
--- a/Aws/SimpleDb/Response.hs
+++ b/Aws/SimpleDb/Response.hs
@@ -9,12 +9,10 @@
 import           Control.Applicative
 import           Control.Arrow               ((+++))
 import           Control.Monad.Compose.Class
-import           Control.Monad.Reader.Class
 import           Data.Char
 import           Text.XML.Monad
 import qualified Data.ByteString.Base64      as Base64
 import qualified Data.ByteString.UTF8        as BU
-import qualified Network.HTTP.Enumerator     as HTTP
 import qualified Text.XML.Light              as XL
 
 data SdbResponse a
@@ -28,27 +26,25 @@
     fmap f (SdbResponse a m) = SdbResponse (f a) m
 
 instance (SdbFromResponse a) => ResponseIteratee (SdbResponse a) where
-    responseIteratee = xmlResponseIteratee $ do
-          status <- asks HTTP.statusCode
-          fromXml status <<< parseXmlResponse
-        where fromXml :: SdbFromResponse a => Int -> Xml SdbError XL.Element (SdbResponse a)
-              fromXml status = do
+    responseIteratee status headers = xmlResponseIteratee (fromXml <<< parseXmlResponse) status headers
+        where fromXml :: SdbFromResponse a => Xml SdbError XL.Element (SdbResponse a)
+              fromXml = do
                      requestId' <- strContent <<< findElementNameUI "RequestID"
                      boxUsage' <- tryMaybe $ strContent <<< findElementNameUI "BoxUsage"
                      let metadata = SdbMetadata requestId' boxUsage'
-                     innerTry <- try $ fromXmlInner status
+                     innerTry <- try $ fromXmlInner
                      inner <- case innerTry of
                        Left err -> raise $ setMetadata metadata err
                        Right response -> return response
                      return $ SdbResponse inner metadata
-              fromXmlInner :: SdbFromResponse a => Int -> Xml SdbError XL.Element a
-              fromXmlInner status = do
+              fromXmlInner :: SdbFromResponse a => Xml SdbError XL.Element a
+              fromXmlInner = do
                      xmlError <- tryMaybe $ findElementNameUI "Error"
                      case xmlError of
-                       Just err -> mapply (fromError status) err
+                       Just err -> mapply fromError err
                        Nothing -> sdbFromResponse
-              fromError :: Int -> Xml SdbError XL.Element a
-              fromError status = do
+              fromError :: Xml SdbError XL.Element a
+              fromError = do
                      errCode <- strContent <<< findElementNameUI "Code"
                      errMessage <- strContent <<< findElementNameUI "Message"
                      raise $ SdbError status errCode errMessage Nothing
diff --git a/aws.cabal b/aws.cabal
--- a/aws.cabal
+++ b/aws.cabal
@@ -6,7 +6,7 @@
 -- The package version. See the Haskell package versioning policy
 -- (http://www.haskell.org/haskellwiki/Package_versioning_policy) for
 -- standards guiding when and how versions should be incremented.
-Version:             0.0.1
+Version:             0.0.2
 
 -- A short (one-line) description of the package.
 Synopsis:            Amazon Web Services (AWS) for Haskell
@@ -33,7 +33,7 @@
 -- A copyright notice.
 Copyright:           Copyright (C) 2010 Aristid Breitkreuz
 
-Category:            Web
+Category:            Network, Web
 
 Build-type:          Simple
 
@@ -111,7 +111,6 @@
                        transformers >=0.2.2.0 && <0.3,
                        transformers-compose ==0.1.*,
                        utf8-string ==0.3.*,
-                       wai >=0.3.1 && <0.4,
                        xml ==1.3.*,
                        xml-monad >=0.5 && <0.6