A quick note: If you're an author looking for an agent, did you know about Query Tracker? I didn't, not really.
It's free, first off.
You can just do an agent or publisher search. If you've got an author in mind, you can see who represents them. They have a forum. It'll keep track of your queries for you (and you can mark agents in your records there, as agents not to query, as rejected, etc. etc.). You can leave comments on agent pages so others know if they're a "no reply means no", etc.
I've only just signed up, and not ready to actually query yet. But it's really neat, and I wanted to make sure people knew! Have you used Query Tracker in your agent search? Do you have an agent, you lucky dog? ;)