Bluetooth is a short range wireless communication protocol used commonly in portable devices.
The most common application you may have seen is those wireless cell phone headsets -- the phone and the headsets use Bluetooth to "talk" to each other.
Basically, if you have a Bluetooth enabled PocketPC (almost all of them are), it could "talk" to the range finder wirelessly and get data from it. Then it would just be a matter of having software designed to take advantage of the data (ie, that looks for this data and automatically enters the range and slope info obtained by the range finder for you), and you might never have to manually enter range data into your PDA ballistics program again.
Edit: Beat me to it, Roy! Didn't mean to step on your toes there. I got distracted while composing my reply