Digging around yesterday I stumbled across QueryTracker (http://querytracker.net). I played around with it a little bit and found lots of info on my first pick agent, decided to join with the free membership, posted my rejection letter, and poked around a bit. I've since decided that I'll probably use it to track all of my queries after all. I was planning on just keeping them in my email, but as many times as I've accidentally deleted stuff, I figured this may be a safer bet.
Plus there's all sorts of helpful information, other authors on-line to chat with, and it's kind of a support group of sorts.
Now I just need to get off my duff and join Monica Ferris' Sisters-in-Crime group and become a guppy. After all they hold several conferences within driving distance for me and at a reasonable price, so for $15 for annual membership I figure it's worth the bucks.