This may help:
That site is a good reference, but also has some outdated info about cards that should work (or used to work, and no longer work correctly, like the Ralink RT2500 USB series).
Currently, I'm using an SMCWUSB-G usb adapter by SMC on my laptop, and it works like a charm with ndiswrapper.
However, should ndiswrapper not work for you, there are another two opensource drivers that work with this card.
The SMCWUSB-G that I have carries a Zydas ZD1211B chip. If you plan on buying it, just make sure the chip is the same by asking the retailer (sometimes manufacturers change the card chip even in the same card model, and normally don't make any reference to that change).
Some tips from cards to stay away from:
- Cards with USB Atheros chips (you need to recompile your kernel to change the stack size...blablabla boring stuff...)
- Ralink RT2500USB (or RT2570). Used to work, but no longer does with the latest 2.6 Linux kernels (causes crashes).
Some cards I know can work, but have not used or extensively tested them myself:
- Ralink RT73 based cards (I think Sitecom sells a USB adapter with this chip)
- Broadcom chips (usualy works with ndiswrapper but can be flaky)