Verified answer

itunes just works with ipods

You can still buy songs and use them on other mp3 players if you change the default of itunes to mp3 first by going to edit/preferences/advanced/import

then you buy the song, which will be in a protected aac format, burn the song to a cd then reimport that song back into itunes. The song will then be unprotected and in mp3 format and can be used on pretty much any other program

i know it doesnt work with a zune.

im not sure about others tho.

sorry