I love having two 24" monitors on my desk. They're 1920x1200 resolution, so combined they provide a pixel count (and the number of square inches) that's higher than you get in one 30" monitor, for about half the price.
It's particularly great if you run any IT stuff on your machine like a SQL database or web server or VMware - it's convenient to have the server stuff on one screen and the client stuff on the other. If you use any remote access apps you can run the remote sessions on one monitor and local stuff on the other. You can also run Winamp or a video on one monitor and do real work on the other!
If you run Windows, you can use a program like ultramon to control how different windows get displayed on your multiple monitors.
I don't do any gaming, however. If I were ever make the gaming leap, I'd get a 30" monitor to use as a third monitor, along with a good graphics card (right now I'm happy with a 4650 to power the two monitors as I don't do gaming or watch videos on that computer), and put it in the middle of the current 24-inchers. That way, one could use the high-res feature of the 30" monitor for some games, and all three monitors for eyefinity-enabled games (do such things exist?) and for general computing.
I understand that the gaming results with a 30" monitor are noticeable vs. a smaller monitor because of the better resolution (2560 x 1600 vs 1920 x 1200 or lower). You need a reasonably high powered GPU to reap the benefit of this however. For other things having two monitors is great - you can watch a movie in fullscreen mode on one monitor while being productive on the other.
If that motherboard has onboard graphics and it's your plan to use 'em you may either be unable to use two monitors and will probably be unable to use it for gaming.