See what iPhone users are listening to with SongStumblr
SongStumblr by Frimby uses your iPhone's 3G and Bluetooth abilities to let you see what others are listening to around the world as well as around the block, as well as share your own musical tastes.
http://rss.macworld.com/click.phdo?i=688bf5551545f882dba38b0ae324966a