Using MP3 players or ipods in class

I would really like to use a devise like an ipod nano in class to show videos of classwork lectures assignments and lab instructions. it seem like a good idea to have kids who have ipods already just use theirs. my problems is that ipods sync to only one computer. Is there a way a kid could come to my class and add a video I made their ipod? If I were able to get some should I go all ipod or is there a better device? is anyone using these that can help?