There used to be some "Game Adapters" available from Netgear and also D-Link that I knew of. They have not been available for sometime now as far as im aware, but you would just use a cheap access point that supports client mode to do the same thing.
If your meaning an xbox 360, then there is an adaptor from M$ available for them but I think its probably cheaper to go with the above option there too.
Bookmarks