Wireless Network Help

Wonder if anyone can give me some advice.

Have just got a laptop which I'd like to connect wirelessly to the net.

Currently, I Tiscali broadband 1mb and have my desktop plugged into a Sagem F@st 900 modem.

Basically, I'd like to set up a wireless network as cheaply as possible. Have already got a wireless card for the desktop (used to be on a wireless network) and need to get one for the laptop. I know I can get a wireless router, and Tiscali have tried to get me to buy their wireless modem, but I'm looking for a cheaper solution.

Is there any way I can connect the laptop to the desktop without a router, or is there a doubler so I can plug two machines into the modem somehow?

Any advice would be much appreciated.

Thanks,
Jamie