I've been using AmbiCom WL1100B wireless CF-card for just about a year now, using it both on my PPC's and laptop's and most say I'm very impressed.
Besides the size of it (they don't sell the "B" card anymore, and the "C" is a lot smaller), it's the best card I've ever used!
Here's a picture of it in my old Casio E-200:
http://www.pdanorway.com/images/WLAN_heimen.jpg
