Logitech's Z-5 speakers: Not in the same league as Z-10s, but decent for the price
CNET has a full review of Logitech's Z-5 USB PC speakers, which cost $80 and are compatible with Windows and Mac latops and desktops.
A couple of years ago, Logitech brought out the, an interesting set of PC speakers that featured USB connectivity and a digital readout on the front of one of the speakers. They looked good, sounded decent, and were cutting edge in their nod to visually incorporating digital-music playback--though the touch-sensitive controls did cause issues for some users. Now the company is serving up the Z-5s, which don't feature the fancy digital readout, but offer some intriguing design elements and the same USB connectivity.