Automatically turn on your speakerphone. While the application is running, when an incoming call is received, the speakerphone of your device will automatically turn ON when you receive the call. You can also automatically activate the speakerphone when you are making an outgoing call by checking the Outgoing ON in the menu. It should work on smartphone and PocketPC WM5/WM6.

http://forum.xda-developers.com/showthread.php?t=369399