(1) What is the best way to backup my 30G iBook hard drive? Could I use a 20G iPod to do a selective backup, and then use the remaining space on the iPod to store its music files? How about an external firewire DVD burner? Any recommendations?

Play with Disk Copy, and its ability to create image files. Last time I backed up my Cube, I created one on my Linux box, dragged all my files into it, then reloaded the machine with Jaguar. Putting all the files inside a disk image like that preserved all the Mac specific file conventions.

GPS, not sure. I haven't really looked, because I figure my Garmin V is pretty PC independant. For the rare occasion of map loading, Virtual PC and a USB->Serial converter should work.