I have a Belkin F8T020 that worked perfectly (or so I recall) and easily under Cacko, but is a PAIN to get working under pdaX.
I know people have had luck with Socket cards, but I don't know if certain revisions don't work. The benefit there is that it doesn't stick out at all.
There's a website
here that lists supported cards. No idea on how up-to-date it is, though, and it seems to only go for SHARP ROM/Cacko.
Hope that helps.