diff --git a/src/Main.hs b/src/Main.hs
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -15,7 +15,7 @@
 ) where
 
 
-import Network.VRPN (Device(..), closeDevice, mainLoops, openDevice)
+import Network.VRPN (Device(..), mainLoops, withDevices)
 import System.Environment (getArgs)
 import System.IO (hFlush, stdout)
 
@@ -46,6 +46,5 @@
           |
             name <- names
           ]
-    remotes <- mapM openDevice devices
-    mainLoops (return False) (10 :: Double) remotes
-    mapM_ closeDevice remotes
+    withDevices devices
+      $ mainLoops (return False) (10 :: Double)
diff --git a/src/Network/VRPN.hs b/src/Network/VRPN.hs
--- a/src/Network/VRPN.hs
+++ b/src/Network/VRPN.hs
@@ -65,6 +65,7 @@
 -- * Operations on devices
 , openDevice
 , closeDevice
+, withDevices
 , mainLoop
 , mainLoops
 -- * Time
@@ -73,7 +74,7 @@
 ) where
 
 
-import Control.Monad (unless)
+import Control.Monad (unless, when)
 import Foreign.C.String (CString, withCString) 
 import Foreign.C.Types (CDouble(..), CInt(..), CLong(..))
 import Foreign.Concurrent (newForeignPtr)
@@ -480,6 +481,18 @@
 closeDevice (RemoteDevice (device, _)) = finalizeForeignPtr device
 
 
+-- | Operate on devices.
+withDevices :: (Enum s, Enum b, Enum d, RealFloat a)
+            => [Device s b d a]          -- ^ The devices.
+            -> ([RemoteDevice] -> IO ()) -- ^ The operation.
+            -> IO ()                     -- ^ The action for operating on the devices.
+withDevices devices operation =
+  do
+    remotes <- mapM openDevice devices
+    operation remotes
+    mapM_ closeDevice remotes
+
+
 -- | Run the main loop of a device *once*.
 mainLoop :: RemoteDevice -- ^ The device.
          -> IO ()        -- ^ An action for running the main loop of the device *once*.
@@ -495,7 +508,8 @@
 mainLoops exitCallback milliseconds devices =
   do
     mapM_ mainLoop devices
-    sleep milliseconds
+    when (milliseconds > 0)
+      $ sleep milliseconds
     exit <- exitCallback
     unless exit
       $ mainLoops exitCallback milliseconds devices
diff --git a/vrpn.cabal b/vrpn.cabal
--- a/vrpn.cabal
+++ b/vrpn.cabal
@@ -1,5 +1,5 @@
 name:                vrpn
-version:             0.2.0.0
+version:             0.2.1.0
 synopsis:            Bindings to VRPN.
 description:         See \<<https://github.com/vrpn/vrpn/wiki>\> for information on VRPN.  This has been tested using VRPN 07.30 on Linux.
 license:             MIT
@@ -12,7 +12,7 @@
 cabal-version:       >= 1.10
 homepage:            https://bitbucket.org/bwbush/vrpn
 bug-reports:         https://bwbush.atlassian.net/projects/HVRPN/issues/
-package-url:         https://bitbucket.org/bwbush/vrpn/vrp-0.2.0.0.tar.gz
+package-url:         https://bitbucket.org/bwbush/vrpn/vrp-0.2.1.0.tar.gz
 
 extra-source-files:  ReadMe.md