Wireless adhoc network for pc and mac

Hi,

I share a flat with a mate and have just had a blueyonder cable
connection installed. It is only USB and is in the room with the PC
running windows XP. My mate has a Mac G4 and wanted to share the
Cable connection for the net. Rather than running cable, from my
network card to his,
I was wondering if any one knows if it is possible to get 2 wireless
cards and set up an adhoc network between a pc and a mac?

Unfortuantely I can't use the ethernet connection from the cable modem
(it has been disabled) where I could get a wireless switch and then
have that running.

I wanted to find out it was possible before I went out and wasted the
money on some wireless cards.

Is it even possible for network sharing between a pc running xp and a
mac with os9?

Any information or points to links or whatever would be appreciated...



Trav