Would it be possible to have access to a user Recent Activity?
I know that this is not a public information on the website, but I think that most part is public. I only see one Activity that should be private: when you down-vote something.
Having access to this would allow to write application that can notify you when a new comment has been added to a question/answer, when an answer is added to your question and monitor upvote/downvote on your question/answer.
It would really be great!