From time to time, I install UniFi access points for customers. These customers normally do not need a controller and just want a nice looking AP. NVX from the UBNT forums put together the firmware needed to convert the UniFi to a standard UBNT radio.
Here is the original post: http://forum.ubnt.com/showpost.php?p=389380
I have mirrored the files here: AirOS 5.5.2 for UniFi.zip (10.65 mb)