diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -4,8 +4,6 @@
 Table of Contents
 -----------------
 
-* [Usage](#usage)
-* [API](#api)
 * [Contribute](#contribute)
 * [Licence](#licence)
 
@@ -34,8 +32,8 @@
 import Network.Metric
 
 main = do
-    sink <- open Ganglia "localhost" "1234"
-    -- Creates ganglia key: "name.space.bucket" with an "int32" type
+    sink <- open Ganglia (Just "thishost") "localhost" "1234"
+    -- Creates ganglia key: "thishost.name.space.bucket" with an "int32" type
     push sink $ Counter "name.space" "bucket" 1234
     close sink
 ````
@@ -49,7 +47,7 @@
 import Network.Metric.Sink.Graphite
 
 main = do
-    sink <- open "localhost" "1234"
+    sink <- open Nothing "localhost" "1234"
     -- Creates graphite key: "name.space.bucket"
     push sink $ Counter "name.space" "bucket" 1234
     close sink
@@ -64,7 +62,6 @@
 Preliminary API documentation is available [on Hackage](http://hackage.haskell.org/package/network-metrics).
 
 > The API is currently in flux, and conversion between the universal `Counter`, `Gauge`, and `Timing` ctors to the respective sink types is not yet completed.
-
 
 <a name="contribute" />
 
diff --git a/network-metrics.cabal b/network-metrics.cabal
--- a/network-metrics.cabal
+++ b/network-metrics.cabal
@@ -1,5 +1,5 @@
 name:               network-metrics
-version:            0.3.2
+version:            0.4
 synopsis:           Send metrics to Ganglia, Graphite, and statsd.
 license:            OtherLicense
 license-file:       LICENSE
diff --git a/src/Network/Metric.hs b/src/Network/Metric.hs
--- a/src/Network/Metric.hs
+++ b/src/Network/Metric.hs
@@ -47,7 +47,7 @@
 --
 
 -- | Open a new sink specified by SinkType
-open :: SinkType -> Host -> HostName -> PortNumber -> IO AnySink
+open :: SinkType -> Maybe Host -> HostName -> PortNumber -> IO AnySink
 open Ganglia  = GangliaSink.open
 open Graphite = GraphiteSink.open
 open Statsd   = StatsdSink.open
diff --git a/src/Network/Metric/Internal.hs b/src/Network/Metric/Internal.hs
--- a/src/Network/Metric/Internal.hs
+++ b/src/Network/Metric/Internal.hs
@@ -110,7 +110,7 @@
     measure (AnyMeasurable m) = measure m
 
 instance Measurable Metric where
-    measure = flip (:) [] . id
+    measure = flip (:) []
 
 instance Encodable Int where
     encode = BS.pack . show
@@ -134,8 +134,9 @@
 --
 
 -- | Combine a Host, Group and Bucket into a single key
-key :: Host -> Group -> Bucket -> BS.ByteString
-key h g b = BS.intercalate "." [h, g, b]
+key :: Maybe Host -> Group -> Bucket -> BS.ByteString
+key (Just h) g b = BS.intercalate "." [h, g, b]
+key Nothing g b  = BS.intercalate "." [g, b]
 
 -- | Helper to curry a constructor function for a sink
 fOpen :: Sink a
diff --git a/src/Network/Metric/Sink/Ganglia.hs b/src/Network/Metric/Sink/Ganglia.hs
--- a/src/Network/Metric/Sink/Ganglia.hs
+++ b/src/Network/Metric/Sink/Ganglia.hs
@@ -37,9 +37,10 @@
 import Data.Binary.Put
 import Data.Bits                ((.&.))
 import Data.Char                (toLower)
-import Data.Data                (Data, Typeable)
+import Data.Data                (Data)
 import Data.Default             (Default, def)
 import Data.Int                 (Int32)
+import Data.Maybe               (fromMaybe)
 import Data.Typeable            (Typeable, typeOf)
 import Data.Word                (Word32)
 import Network.Socket           (SocketType(..))
@@ -76,10 +77,10 @@
     def = defaultMetric
 
 -- | A handle to a Ganglia sink
-data Ganglia = Ganglia Host Handle deriving (Show)
+data Ganglia = Ganglia (Maybe Host) Handle deriving (Show)
 
 instance Sink Ganglia where
-    push (Ganglia host hd) m = mapM_ (hPush hd) (concat . map enc $ measure m)
+    push (Ganglia host hd) m = mapM_ (hPush hd) (concatMap enc $ measure m)
       where
         enc (Counter g b v) = put host g b v Positive
         enc (Timer g b v)   = put host g b v Both
@@ -107,7 +108,7 @@
     }
 
 -- | Open a new Ganglia sink
-open :: Host -> HostName -> PortNumber -> IO AnySink
+open :: Maybe Host -> HostName -> PortNumber -> IO AnySink
 open host = fOpen (Ganglia host) Datagram
 
 -- | Encode a GangliaMetric's metadata into a Binary.Put monad
@@ -139,7 +140,7 @@
 
 -- | Oh, the horror
 put :: Encodable a
-    => Host
+    => Maybe Host
     -> Group
     -> Bucket
     -> a
@@ -151,7 +152,7 @@
      metric = defaultMetric
          { name  = bucket
          , group = group
-         , host  = host
+         , host  = fromMaybe "" host
          , value = encode value
          , type' = determineType value
          , slope = slope
diff --git a/src/Network/Metric/Sink/Graphite.hs b/src/Network/Metric/Sink/Graphite.hs
--- a/src/Network/Metric/Sink/Graphite.hs
+++ b/src/Network/Metric/Sink/Graphite.hs
@@ -29,7 +29,7 @@
 import qualified Data.ByteString.Lazy.Char8 as BL
 
 -- | A handle to a Graphite sink
-data Graphite = Graphite Host Handle deriving (Show)
+data Graphite = Graphite (Maybe Host) Handle deriving (Show)
 
 instance Sink Graphite where
     push (Graphite host hd) m = do
@@ -48,7 +48,7 @@
 --
 
 -- | Open a new Graphite sink
-open :: Host -> HostName -> PortNumber -> IO AnySink
+open :: Maybe Host -> HostName -> PortNumber -> IO AnySink
 open host = fOpen (Graphite host) Stream
 
 --
@@ -57,7 +57,7 @@
 
 -- | Encode a metric into the Graphite format
 put :: Encodable a
-    => Host
+    => Maybe Host
     -> Group
     -> Bucket
     -> a
diff --git a/src/Network/Metric/Sink/Handle.hs b/src/Network/Metric/Sink/Handle.hs
--- a/src/Network/Metric/Sink/Handle.hs
+++ b/src/Network/Metric/Sink/Handle.hs
@@ -26,7 +26,7 @@
 import qualified Data.ByteString.Char8 as BS
 
 -- | A generic sink handle
-data SinkHandle = SinkHandle Host (String -> IO ())
+data SinkHandle = SinkHandle (Maybe Host) (String -> IO ())
 
 instance Sink SinkHandle where
     push h = mapM_ enc . measure
diff --git a/src/Network/Metric/Sink/Statsd.hs b/src/Network/Metric/Sink/Statsd.hs
--- a/src/Network/Metric/Sink/Statsd.hs
+++ b/src/Network/Metric/Sink/Statsd.hs
@@ -33,7 +33,7 @@
 data Sampled = Sampled | Exact | Ignore
 
 -- | A handle to a Statsd sink
-data Statsd = Statsd Host Handle deriving (Show)
+data Statsd = Statsd (Maybe Host) Handle deriving (Show)
 
 instance Sink Statsd where
     push (Statsd host hd) m = mapM enc (measure m) >>= mapM_ (hPush hd)
@@ -49,7 +49,7 @@
 --
 
 -- | Open a new Statsd sink
-open :: Host -> HostName -> PortNumber -> IO AnySink
+open :: Maybe Host -> HostName -> PortNumber -> IO AnySink
 open host = fOpen (Statsd host) Datagram
 
 --
@@ -58,7 +58,7 @@
 -- | Encode a metric into the Statsd format
 -- *TODO:* Currently statsd sampling is not exposed via the global metric type
 put :: Encodable a
-    => Host
+    => Maybe Host
     -> Group
     -> Bucket
     -> a