I am developing for Android 4+ with Eclipse Juno ADT bundle + Google Plugin for Eclipse. I need to programmatically log into a google account to use the Google Calendar API.
OK, I've found out what I was missing.
Ensure you have downloaded the Android SDK Services -> Extras -> Google Play services
Follow the instructions provided by the following link to add the google-play-services-lib library to your project:
http://developer.android.com/tools/projects/projects-eclipse.html#ReferencingLibraryProject
Best Regards