Getting the people block going (where they can't publicly reply to you) I think was near the top of my list, followed by CH. Those should be some nice, large projects.
Bob...Lets' say that you and I discuss IBM. So, I want to track that post down. If I type in Bob, I get a gazillion posts. If I type in IBM I get a gazillion others. However, if I can type in Bob and IBM, I should quickly find the post I'm looking for. By member and subject.