dab?
Generally, any device that has a headphone/rca audio output can be plugged into PC speakers. Depending on exactly what outputs/input you have, you may be able to just plug everything in, or you may have to buy an adaptor (which are usually a few dollars form any electronics store).
If your computer speakers have a 3.5mm plug as their input, they can be plugged into anything with a 3.5mm socket output (like a walkman or mp3player).
Why did you want to know? Do you already have the speakers/device. If so, i might be able to give you more specific details.
RoD