BTFileTransfer is a subclass of NSObject that lets you transfer any kind of data (from simple text to complex files) via Bluetooth.
Great for "bumping" a vCard or settings between two devices.
The demo app included with your purchase lets you send photos from one iOS device to another (tested and confirmed working on iPhone, iPad and iPod Touch).
Deployment target: Tested with iOS 5 and later
Bonus 1: Buyers of the developer license can request features that might be implemented later
Bonus 2: Demo app "BTChat" available to everyone soon after release (like Messages app but Bluetooth) [Screenshot]