I've found that not too many of my coleagues know that almost every google application has its own API. E.g. the google calendar has API that is available in .NET. I am interested in the calendar automation so I hope I will find some time to use the Google Calendar APIs and Tools.
Anyway all that is available for developers in google applications is avialable here: http://code.google.com/
Just check it. Maybe you will find something interesting for you.