There are a few ways to do this. There is the Raphnet adapter, a Mayflash one with dual ports (That appears to have problems), the Japanese Elecom adapters.. all of these are kind of expensive, IMO, for what they do. Anyways, i was in BestBuy and saw this for $13 CAD..

.. The controller is mostly trash (Dpad
sucks) but the adapter seems to work quite well . I am not set up to test lag but it "feels" responsive.
The USB adapter is only a few inches long (my Elecom is 3.3 feet).
Thought i'd share.