rtl8180 under linux 2.6
You need to use ndiswrapper and the driver from the RealTek site; using the driver provided on the CD that came with my cheapo pcmcia card led to a panic on startup.
Update: According to Russel Phillips (some guy I don't know--his words :-) Realtek have recently released a Linux 2.6 driver for this chap. I've not tested this yet, as I'm not sure where I put the pcmcia card, and the ipw2200 driver for my internal wifi works like a champ.