I'm looking for a wireless PC card for AirSnort. The Airport Extreme built into my Powerbook doesn't fully work, and I want a card that will work natively without any issues with AirSnort.
Do you mean it doesn't work broken wise, or it lacks functionality needed for whatever you're doing wise? If it's broken, and your PowerBook is less than 1 year old, or if you have purchased Applecare, you could send it in to get fixed.
I recommend
Linksys WPC54G Wireless-G Notebook Adapter
It will work on MacOs with minor tweaking.
G is backwards compatible with B
You could always get an ABG card
There are also (near future)WinMax, (near future)wifi-N and GPRS cards out there