I may get flamed for asking, but I've always wondered..
Why don't the StackExchnge sites have any mechanism for “making friends", or at least keeping track of people you like, find interesting, want to harass, etc. ?
I often click through to the account profiles of people who I have seen answer questions with particular insight or uncommon knowledge - to see what other topics they have posted on, etc. There is, however, no way to keep tabs on these people. Unless I bookmark their particular page, I'm unlikely to happen upon it again.
For an ecosystem that depends so heavily on people's willingness to interact with each other, this seems like a pretty antisocial omission.