I've got a Linksys Wireless CompactFlash card, WCF12.
It's good for short periods, however it gets rather hot after a while and it will freeze the zaurus. My PCMCIA wifi card on my laptop does the EXACT same thing, just takes longer, so i assume most wifi cards do this after a few hours?
Its a good card though, still works after being hot enough to burn my fingers heh.