I recently picked up the Bluetooth moduleRN-42 This was a cheap low cost way to integrate Bluetooth into an upcoming project. First up was getting the pieces soldered. Thanks to Walter over at Walter's Epic Blog he hooked me up with a great soldering job.
I got the itch a little bit ago and started doing some research on building an Android App to communicate with this thing (with the eventual plan to hook it up to a microcontroller). I found BlueTerm this program connects to a Bluetooth Device and sends UART data across.
I started thinking to myself I wonder how I can echo the data back without having to build the UART up for my microcontroller. I asked the question over at electronics.stackexchange, and of course being the impatient type I just jumped in and hooked the rx to the tx lines.