1. Make sure you have the Android SDK installed http://developer.android.com/sdk/index.html
2. Once installed and have the various versions downloaded there should be a tool in the "Tools" folder.
3. C:\Program Files\Android\android-sdk\tools\DDMS.bat (on windows)
DDMS will pull up an app. As long as you are connected via ADB (either via USB or via adb connect IPaddress:5555 both work - Instructions on ADB here >>> http://forum.gtvhacker.com/revue/topic31.html
DDMS will let you take a screen shot.
Screenshot of my phone showing up (not at home to test with my Revue)
Screenshot of where to capture a screen shot