Over at Wired's Gadget Lab they've got a rundown of a neat new feature of iTunes 8.1: iPhone / iPod touch voting for songs in DJ mode. Basically, Apple also released an update to their Remote application to go with iTunes 8.1 and it is now possible to set up iTunes so that anybody with an iPhone or touch connected to the same network can actually request songs from your library into the DJ list (formerly Party Shuffle playlist). Once songs are queued up, other guests can even vote on the songs (presumably to move them up the queue, though that's not confirmed). You can still control all playback features via Remote on your own, authorized iPod touch or iPhone.
This is a brilliant piece of integration from Apple. Invite your friends over (though only if they have an iPhone or touch, naturally) and let the guests choose the songs. There are apparently some annoyances and quirks to the system in the way the queuing actually works, but one imagines those will be worked out in the future.