The router supplied by VM (DLINK DIR-615) doesn't have a USB port at all. If you're looking for a decent router that will do that, might I suggest you keep an eye out for the new Netgear WNR3500L? It's due out any day now, will run third party firmware such as DD-WRT (the 'L' stands for Linux) and has USB. DD-WRT will allow you to use the USB port for NAS, WAN-facing FTP and HTTP serving and all that jazz.
The WNR3500L is also quite a beast by all accounts, and has great routing and WAN>LAN and WLAN>LAN speeds. I can't wait to grab one to try tbh.
