http://www.noteflight.com is a great site. If you find a song you like you can download it, make sure it's the "For Musical Performance MIDI" and if it's in two clefts it seperates them to two separate hands .
(Also, I see what the difference is between the two MIDI export modes. One preserves dynamics and whatnot. The other fills out all the note durations so it imports better. The "for musical performance" throws my sheet music generator for a loop. The "for import in another program" generates beautiful sheet music. hehe.)