Don't know if works on Zaurus, but I'm just trying to help the community.
CF bluetooth card with a buit-in 128bit encryption.
$25 through ubuyit.
Check it out http://www.ubid.com/actn/opn/getpage.asp?AuctionId=601426436
Also I found this:
Sandisk 802.11b 128MB CompactFlash CF w/ Wi-Fi - NEW Free Ship
$56 through ubuyit
Check it out http://www.ubid.com/actn/opn/getpage.asp?AuctionId=601428371