Limit one computer's network bandwidth?

Is it possible to limit the bandwidth of one of the computers on a network? My brother is always downloading or playing games on the internet and it makes it impossible for anyone else to use the internet. Also I watch films from my pc on my laptop and when he is playing or downloading the films lag unbearably. So I want to stop him using up all the bandwidth. Any suggestions?
P.S. All the computers on the network are wireless G execpt his which is wireless B.
Cheers

 

There is, but you would have to have a router that does it. Also there would be no way to limit him from changing IP's, unless you use Static addressing. I would make him get his own broadband if it is that bad.