http://www.handango.com/This is the only product in the market that allows HTC 3g users to switch between 3G-2G in one click. It allows two controlling connections, BT and WIFI with or without limit.
Take control of your connections: Switch between 2G-3G Enable and disable connections. Disabling connections makes it impossible to use them so you know they won't generate traffic data. Establish and close connections. Set a time frame where connections wont be allowed (i.e., when you are sleeping) saving money and battery.. Turn off/on Bluetooth and Wifi with or without time limit. When the limit expires then it is set to off state.
Windows Mobile 5.0 Phone Edition
* HTC P3600
* HTC TyTN
* Qtek 9000 (5.0)
* Vodafone VPA IV (5.0)
* i-mate JASJAM
* i-mate Jasjar (5.0)