Yes you can do it. You gotta buy a usb A-A ethernet adapter.(not sure is it A to A or B to B) anyway, the cable is like 20-30 bucks in compUSA for a 5 foot long cable. I wouldnt recommend it as it only have a 10base T connection. Go with the regular nic PCI card on your PC and buy a ethernet adapter on your lappy for like 9-20 dollars. It should be better. Faster transfer! and longer cable.
If you really need usb for your laptop, go with like a farallon usb adapter. It connects to your laptop through the A interface and then gives you a RJ45 port on the other end. Good if your switch or sever is far from your work space.(hint: you got to wire your place up though, I have over a 100 worth of cables routed in my place.)
Hope it helps. Later