diff --git a/hissmetrics.cabal b/hissmetrics.cabal
--- a/hissmetrics.cabal
+++ b/hissmetrics.cabal
@@ -1,5 +1,5 @@
 Name:                hissmetrics
-Version:             0.2.1
+Version:             0.2.2
 Synopsis:            Unofficial API bindings to KISSmetrics.
 Homepage:            https://github.com/meteficha/hissmetrics
 License:             BSD3
@@ -32,5 +32,7 @@
                  , http-types
                  , http-conduit == 1.4.*
   Extensions:
+    DeriveDataTypeable,
     RecordWildCards,
     OverloadedStrings
+  GHC-options: -Wall
diff --git a/src/Web/KISSmetrics.hs b/src/Web/KISSmetrics.hs
--- a/src/Web/KISSmetrics.hs
+++ b/src/Web/KISSmetrics.hs
@@ -9,6 +9,7 @@
     , SimpleText
     , Property
     , Timestamp(..)
+    , generateTimestamp
       -- * Making calls
     , call
     , CallType(..)
@@ -17,13 +18,14 @@
     , Identity(..)
     ) where
 
+import Control.Applicative ((<$>))
 import Control.Arrow (second)
 import Data.Text (Text)
-import Data.Time (UTCTime, formatTime)
+import Data.Time (UTCTime, formatTime, getCurrentTime)
+import Data.Typeable (Typeable)
 import qualified Data.ByteString.Char8 as B8
 import qualified Data.Conduit as C
 import qualified Data.Conduit.List as CL
-import qualified Data.Text as T
 import qualified Data.Text.Encoding as TE
 import qualified Network.HTTP.Conduit as H
 import qualified Network.HTTP.Types as H
@@ -52,9 +54,18 @@
     Automatic
     -- ^ Use KISSmetrics' servers time as the timestamp.
   | Manual UTCTime
-    -- ^ Use given time as the timestamp.
+    -- ^ Use given time as the timestamp.  If possible, use
+    -- 'Manual' since it allows you to safely resend events that
+    -- appear to have failed without being afraid of duplicates.
+    -- See also 'generateTimestamp'.
+    deriving (Eq, Ord, Show, Read, Typeable)
 
 
+-- | Generate a 'Manual' timestamp with the current time.
+generateTimestamp :: IO Timestamp
+generateTimestamp = Manual <$> getCurrentTime
+
+
 -- | A type of call that may be made to KISSmetrics.  See also
 -- <http://support.kissmetrics.com/apis/specifications>.
 data CallType event ident =
@@ -83,6 +94,7 @@
           , identity' :: ident
             -- ^ Other identity you want to alias.
           }
+    deriving (Eq, Ord, Show, Read, Typeable)
 
 
 -- | Type class of data types that are event names.