accessing ipod library, current best method?

hello,

the hd on my laptop is reaching it's limits... and i'm on the go, with my ipod in tow. i would like to be able to access the music from my ipod on my macbook pro, and transfer them to my iphone. is this possible? using which programs?

what is currently the best method for accessing the music and library of my ipod? this ipod is synced to my desktop machine, which is at home...

thanks,
r.