Short of purchasing (or otherwise procuring) 3rd party software, I do not know of a way to transfer songs to or from the latest iPods without iTunes. If you have an older iPod (3rd or 4th generation "regular" iPod, for example), there are freeware apps that will let you do it. I honestly haven't looked in awhile for 3rd party software, sorry I can't be more specific. ilounge.com may have some pointers...
Edit: actually, it's fairly easy to get stuff off your iPod using just Windoze Explorer or the Mac equivalent. However, I don't know of a way to get stuff ON your iPod without iTunes or 3rd party software of some sort.
/tk