Bob,
I carry the Roland Edirol UM-1 simple USB interface cable. It includes the windows 98 and Windows 2000 drivers and Macintosh driver for OMS and FreeMid. The price is $55.00 if you are interested. You can also buy a two in and two out, but most of my customers are just wanting the simple one and one unit. It is approx. 3" long by 2" deep and gets it's power from the PC.
George Kaye
Kaye's Music Scene
Reseda, California