USB can only officially travel about 20ft. When I needed some 100ft USB cables, I found a really neat "USB over CAT5" solution. A little $20 converter dongle kit plugged on both ends and it was able to go the distance with no problems. It's in my attic now, I will check the maker when I get a chance tonight.
Mine looked better and had a better price, but Google did find these for "USB over CAT5": TigerDirect Sunset