Network serving from a laptop?

In my university halls we can use the network in our flat to play games.
However there's a probem, only 2 of us can start a game. If either of them sets up a server then everyone can see the game and join it no problem.
If anyone else tries to start a server, noone can see it at all.
We've all tried disabling or completely removing our firewalls and that has no affect so it's not that.
Basically it must be something to do with the way the system's wired.

Is there any way I can set up my laptop (WinXP) as a network server with its WAN card, so that multiple laptops can play over wireless?
(like a computer-to-computer network?)
I also have another laptop, can I use the wireless card to "serve" the internet to my other laptop so I can use both?
It would also be useful to be able to wirelessly map network drives to synchronise my files.


Thanks in advance.
Tom.