awarner is talking about the proprietary USB connector like on the Cingular 3125 for example. It is NOT a standard mini-USB. It is the only port on the phone and it is for charging, syncing, and audio out. This would not be compatible with the Motorola mini-USB headphones that are for the RAZR or, your friend's SLVR.
Devices: T-Mobile MDA (Cingular SIM), i-mate SP5m (sitting in a drawer at the moment while I attempt to migrate to PPC permanently), Cingular 3125 (unlocked and in use on T-Mobile), Motorola MPx220 (retired), Motorola MPx200 (retired)
Accessories: Plantronics Explorer 330 & 2G Patriot Micro-SD (use w/MDA), Kingston 2G mini-SD used in SP5m, Plantronics Discovery 640 & 2G San Disk micro-SD (use w/3125), Jabra A210 BT adapter + Motorola HS805 (retired)