And, for the guy who said his WiFi connection wasn't fast enough to game... If you are talking about gaming on the Internet, then a WiFi connection is very much fast enough. Most WiFi is 54Mb nowadays, and the older stuff is 11Mb.
Two big problems with wifi is that the response times are much more erratic than using a wired connection, and it's more prone to packet loss thanks to the increased potential for interference.
both of those things can greatly affect the ability to play online games, which typically need a very steady connection with very low response times.
(a nearby 2.4GHz wireless phone or a microwave can really wreck havoc with your wifi connection. And even if you don't use any of those, your immediate neighbours very likely are)