Don't worry!
Hi!
No need to worry. Your iPod will work fine with your powerbook, as the Windows formatted iPods can be read by both PCs and Macs. I have one of these iPods and have it formatted for Windows - simply because it allows me to use it with both my iBook and my PC.
In fact, the 3G iPods are also "Windows" (FAT) formatted, which is why they work out of the box with Mac or PC. Just another reason why Macs are great - they can read Windows File Systems, but Windows can't read Mac...
😀