u can do alot of things. can delete song, can play raw video(on my nnao gen1), u can change the theme, u can have more games but i restore back to ipod original software after some time, as it's very inconvenient... if u r using linux / unix then ok, if mac / windows then it's very troublesome. ipod linux using ext2, means if u r not using linux / unix u need special software to access (mount) the storage n transfer song/video. if u r using linux/unix, then just mount it like flashdrive.