I'm using a zaurus (SL-C700), wireless networking *and* keeping my CF slot open. How? There are actually 3 IO ports on the Zaurus, the CF slot, the SD slot and the zaurus connector, which contains USB-client, serial and power connections. There's a product called AirCable which is a serial port to Bluetooth bridge, that snaps right onto the zaurus connector. So, with the zaurus, the aircable and a T610, I've got wireless (but slow) internet access, anywhere the phone can get a GPRS connection.

http://www.aircable.net/

-brendan