I just bought some "end of line" (5 year old !) NETGEAR WPN-511 pcmcia Wi-Fi cards from my local Staples for £7.50 each.
(Since all the internal seals were broken it looks like they were "customer returns" as well as "end of line" so check first before buying and as you may be able to negotiate a bit more discount !)
Anyhow on my xubuntu 9.10 notebook I just swapped my kcorp lifestyle KLS-611 (Ralink RT2500) pcmcia card with the 'new' NETGEAR WPN-511 (Atheros AR5001X+) and rebooted !
Not only did ubuntu instantly recognise the Atheros chipset it even remembered all my SSID & WPA details and automatically linked me to my Wi-Fi network !