i've just started playing with lala.com--it's looking interesting in that it seems that it will give me access to a large chunk of what i've got in itunes via the web, but without having to actually upload stuff (it looks at what i supposedly own on my own computer and matches it up to stuff in its library). also, they've got really good pricing on songs both for streaming only and for mp3 downloading and they've got albums that the itunes music store and amazon mp3 store don't, like Belleruche's Turntable Soul Music.