It doesn't use the USB port but the Apple Airport Express may be a solution to your computer location problem. In theory it requires the use of iTunes but I believe there are some hacks around to make it work with other music players. It has Toslink out as well as an analog minijack so you can use one of your optical in ports. The Airport also avoids the problem of USB audio resampling everything to 48Khz. I've been using one for over a year and it has worked flawlessly, sounds good too.

mike