Something that is strangely missing from the iPhone is the ability to transfer files over a Bluetooth connection. That shortcoming has been overcome with the arrival of iBluetooth, a third-party app that lets beam that song or picture to your fellow Bluetooth-equipped smartphone user.
iBluetooth is in no way endorsed or affiliated with Apple itself and you can't even get this useful application through the regular Apple App Store. Instead, you'll first need to have a jailbroken iPhone and then you can find iBluetooth through the iSpazio repository on Cydia. It's a bit of a workaround, but at least it works. Embedded below is a brief video of iBluetooth in action: