I used a Linksys 54g USB Wifi in OS X and it worked great. I've attatched the kext if you would like it and copied the directions.
Install the DMG and reboot then type the following in a terminal window:
sudo -s (enter your password)
sudo chown -R root:wheel /System/Library/Extensions/RT73USBWirelessDriver.kext
sudo chmod -R 755 /System/Library/Extensions/RT73USBWirelessDriver.kext
cd /System/Library
rm -rf Extensions.mkext Extenions.kextcache
sudo diskutil repairPermissions /
reboot
The usb wifi should be detected as ethernet and you will have to hit apply in network under system preferences.
QUOTE(Jeff Huang @ Aug 27 2008, 07:00 PM)

My laptop's working on a F.2 something version bios. I was thinking more a express card or USB wifi solution. I don't want to have to buy the part and see that my pci-e doesn't work...

any USB or express card options you know of?