I got a second monitor at work, and now I get to experience the awesomeness of two monitors! They really do improve productivity for programming.
I use the first one (my laptop's built in screen, 1920x1200, 17") for primary development (that is, actually writing code) and the second one (1280x1024, 17") for debugging/testing and reading documentation. Maybe I can get a third monitor* for reading Slashdot! :) Maybe I'll post a picture of my office.
*A third one probably wouldn't actually work because my laptop only has one graphics card. So unless I can get my hands on one of those external monitor-joining boxes, I'm limited to two.