I use MobiLuck http://www.mobiluck.com/
MobiLuck is a new way of communicating around you using your mobile phone or PDA.Today, with MobiLuck you can already:
Detect all nearby Bluetooth devices. Your cell phone rings or vibrates when it finds one.Send messages and photos for free to friends or strangers with no need of their phone numbers.Hear when you receive a Bluetooth message and reply to the sender!Send your profile and receive profiles from other MobiLuckers including their photo.
Send MobiLuck to other people so you'll meet more and more MobiLuckers.