There are USB<-Ethernet CAT5->USB cables/adapters around allowing you to go quite a lot further (50m to 100m), but I don't know how they will go power wise for the current draw.
Here's one I googled:
http://www.lindy.com/uk/productfolde...2801/index.php
Note that these are USB 1.1 cables so might not be good for all purposes.
Turbo