Connecting Laptop to my PS2

Hi, I've just purchased a laptop and was hoping to use it to play games
online with my PS2. I've got wireless broadband running through my house
(laptop is connected wirelessly), but no wireless adaptor. I was told that if
I use a cross over cable then I would be able to connect to the net, but so
far no luck. I have found a couple of sites relating to XP, but so far
nothing on connecting using Vista. If anyone has any suggestions on how to do
this, it would be greatly appreciated.