Google accounts has been scaring me of late. Its basically the account to which all your google stuff is linked. Services such as Adsense, Gmail, Google reader, GTalk, Search History, and PicasaWeb are a few I use. New services like feedego are using Google Accounts to authenticate.
A friend of mine recently had his account broken into, and a personal chat was broadcast via his gmail account to a close group of friends. He called me asking if I could help. The email was sent via Gmail, mostly to people on Gmail. I can't get any useful information from IP's that are internal to Gmail (10.x.x.x addresses). Their is no account history which could show you login or logout times or locations. We couldn't tell if my friend had forgotten to log out of a machine. Had his password been compromised? Was one of his machines compromised?
After reading stories such as this and this, I can't believe that Google doesn't provide any more information for your account. Scary.
BTW, feedego seems like a promising service. Its built on Google App Engine. Try it out.