internet connection sharing under linux?

[endrien]

Well I use my laptop mainly as a server,but untill I get my new wireless card for my desktop in a week or 2 I use it as a sort of router,I get wireless on my laptop and use ethernet to my desktop via internet connection sharing.I would be using ubuntu(most likely server edition,maybe not).So I was wondering,how can I do this,and whats the easiest way to do it.
Thanks
~Endrien