On the heels of the Desktop Cradle for the iPAQ rx1950, BoxWave has announced one for the Cingular 8125. It will allow you to synchronize and charge your 8125, supports USB 2.0 speed transfers and includes a 110-240V A/C adapter cable for quicker charging time (not required as you can also charge your 8125 through the USB cable albeit more slowly).
The BoxWave Cingular 8125 Desktop Cradle is available for $32.95 USD (Web special) directly from BoxWave.