i've got a 1st gen iPod for the PC (or 2nd gen iPod- not sure) and am switching now to a powerbook. will my ipod still be able to work with OS X or is there software i'll have to download to reformat it or something?
It will work as is (without reformatting) because Mac OS X works just fine with FAT32 (Windows format) volumes. If you do want to reformat it as an HFS+ (Mac format) iPod, you can. The only advantage to doing that is slightly more space and faster mounting. Anyway, bottom line is, don't worry, it'll work just fine.
After your first sync think about redoing it as HFS+
That way you don't loose music, and your iPod is faster. And its a 2G iPod if the scroll wheel is a trackpad but the buttons are physical, as well as those being the first to natively work with Windows.