What is the least expensive way to get digital audio out of a laptop?

[sync]

All the USB sound cards I've seen have all sorts of inputs and outputs that I don't need. Is there a simple device that just does USB to digital audio?

[Zukeeper]

All the relevant facts are on the web page, but FYI it has one output jack which will put out either analog stereo, or using the included adapter, digital optical.

http://www.turtlebeach.com/site/products/audioadv/micro/

[sync]

Thanks. That looks good. My only concern is their use of an optical connector. I've always avoided them because they seem so flimsy and the cables are so easy to accidently pull out.