What iPhone app shows where other iPhone users are via GPS?

no app does that. Its not leagal yet... its a breach of peoples privacy... but it is doable

it is legal now... i never knew it wasnt :P but the app is called "family map" and it lets you track other iPhone users that are on the same plan. i don't think it is legal to actually track where random people with the iPhone are...through YOUR iPhone. But family is trackable. :) i believer its a $5 app, and that's how much you would have to pay a month. but it's pretty cool 8)