HTC has released an update to Android 2.2 Froyo for the T-Mobile myTouch 3G that launched with Android 2.1.
The update includes Wi-Fi calling, Wi-Fi hotspots, USB tethering, universal search, larger text box, places search, glitch fixes, and ability to store apps on the microSD card. The update will not support mobile Flash because the processor is not fast enough.
In order to update your T-Mobile myTouch 3G, you have to download HTC Sync for T-Mobile my Touch 3G Slide. Task Manager or Task Killer applications
installed on the phone must be turned off and uninstalled to avoid them
interfering with the update process.
Be sure that your phone is at least 30% charged. You will not be able to make or receive phone calls during the update process.