When Android debugger can't attach to the emulator...

If you select an app to debug from eclipse but instead of the app loading up on the emulator you get a message saying: "waiting for the debugger to attach"... best thing (I have found) to do is open up the windows command prompt, enter the command "adb kill-server", wait a second and then enter the command "adb devices". Your debugger at this point should attach to the emulator and your app should load up.