I've had a well versed network tech for a local uni suggest that
orinocco cards are fantastic. I can't remember what he said about
cisco cards. But definately make sure when you pick out something
that you see the device listed by the drivers you intend to use.
I'll second that. I've got an old Dell TrueMobile 1500 802.11b card, which is an ORiNoCo Gold OEM'd. It's only B, and it's 16-bit PCMCIA, but it works pretty much flawlessly in any distro newer than 3 years old or so, I've even used it with an old copy of FreeBSD, say
4.3ish on a 486SLC50 laptop for WarDrving. Very capable, very compatible cards.
Jon.