USBFever carries a great little product that's very useful for computers that don't have volume controls on their speakers. The USB Volume Control (very aptly named) is touch sensitive so all you do is slide your finger along the surface to raise or lower the volume and hold your finger on it it mute or un-mute you speakers. It seems to work very well, but as stated in the specs, it doesn't work for everything, overall though it's a useful little product that inexpensive as well.