This Mobi Products BatteryCradle allows you to easily synchronize and charge your HTC with any USB-enabled computer. Just connect the cradle to your computer's USB and you are set. The Tilt is charged through your computer's USB port.
The cradle also features a spare battery charger - great to have if you have multiple batteries. If you want to use the cradle's spare battery charger, you also need to connect the bundled AC adapter. The AC adapter does not charge the Tilt, it only provides power to the battery slot.
NOTE: If your phone has a extended battery door, you may need to remove it to place your phone in the cradle.