I've drafted a HOWTO for compiling / patching and setting up the drivers for cards based on the Ralink RT2400 chipset for 802.11b PCI/PCMCIA adaptors. It's a bit of a hassle, but these cards are dirt cheap and work well enough in the average home LAN setting.
It's in the forums at Minitar's web site:
I don't work there, I just use one of these cards.
The HOWTO is currently a 3rd-draft and deals with how to create the drivers and set up a network config based on static IP.
I'll add DHCP instructions soon.