I hate to be a thorn in this thread since it's so well developed, but do you have a written, monthly budget? Ideally, you know every penny you're earn and every penny your going to spend before the month even starts (not including real, actual emergencies, example: new tires/brakes are not an emergency). You need to have a real budget before you start the snowball so you know exactly how much you can put toward your debt. (and so you have a much better chance of finishing the plan).
Once you have a budget... HECK YES, snowball it!
If you haven't read it yet, a lot of people in this thread are referring to the book Total Money Makeover by Dave Ramsey, might be worth spending the $10-$20 on.
Cheers,
-SM
Starting Score: ~470 preBK(8/2010)