What would it take to be able to share your music via airplay with someone else who has an iPhone? Say you're at the gym working out, using your iPhone with your headphones, listening to music. Wouldn't it be cool to let your friend hear what you are listening to by sharing your music via airplay? I know this isn't possible today but is it conceivable? Would both phones need to be on the same wifi network for this to work or would the sharing occur via Bluetooth?