O'Reilly reviews the Wireless Ethernet module
O'Reilly Network has an excellent review of the Xircom Wireless Ethernet module.
The review includes information on connecting to unencryped and encrypted networks, as well as some of the quirks the reviewer faced.
I hope to get my hands on a review unit soon. I've been itching to have an excuse to get a wireless Airport card for my PowerBook, and now I have one.