So if Apple ever releases an SDK here’s an idea:
Why not let iPhones see each other when they are in range of Bluetooth or Wireless? You could have some kind of functionality like “Send my vCard to xxx” or “Send this photo to xxx”.
You could get a list of all iPhones within range (you could have a setting that allows your iPhone to be seen or not) and ‘flick’ or ‘drag’ items to them. Hell, even have a feature where the iPhone would buzz when a certain someone was within range.
You could share anything. vCards, music, photos, bookmarks, locations (in gmaps), etc.
Pretty cool, don’t you think?