dual 19" Mitsubishi Diamond Pro 900u's on my XP1800+ and a 15" LCD on my 550...
my desktop let's see how many hits I'll get
edit:
whoops, forgot to say what I use it for... when I'm just messing around, say browsing OT and what not, I have one monitor displaying IE windows, and the other for my putty session to my headless linux box running BitchX and AIM

I have my other computer up top running AIM, ICQ, and Outlook. When I'm actually doing schoolwork, I usually have one monitor running my development environment (usually some putty sessions or xterm windows and some shells, or VC++ or MS Word) and reference material such as my buddies on AIM, IRC, and you guys on ATOT

codegurus.net helps sometimes too
edit2:
here's the stats before I posted on ATOT...
http://www.modemboy.net/desktop.jpg 13 (0.7%) 4560k (19.7%)
I'll check later on tonite to see how many of you actually went
