Smart Mobile Tools released BlueStarter, a Windows Mobile tool to automatically start an application when a configured bluetooth device is discovered.

Features:

Starts an application on bluetooth device discovery
Easy Bluetooth device selection
Optional application start arguments
Low power consumption (no background service running)
Test option using the test button
2 search modes; on a timed event or on wake up (power button pressed)

http://smartmobiletools.freehostia.com/node/2