I am trying out Core Bluetooth framework introduced in iOS 5.0. According to many threads (one of many) on StackOverflow itself:
As spamsink commented, one device needs to act as peripheral, and one as central in order for them to communicate.
There is a great sample app from Apple that does that. Also, check out WWDC 2012 sessions 703 - CoreBluetooth 101 and 705 - Advanced CoreBluetooth for great explanation and examples of CoreBluetooth framework usage.
Also note, for device to be in peripheral mode, it needs to be updated to iOS 6.0 or later.