I went to Fry's today and picked up an Airlink AWLC6070 Wireless N PCMCIA card for only $12.99 (regular price: $39.99). I am not sure it will still be at this price past today, but it would be worthwhile for anyone wanting to upgrade the weak Airport card of the PowerBook.
You have to download the Mac drivers from RAlink as the drivers included with the card are strictly Windows. You can get the drivers here from their Taiwan site (the US site doesn't have these drivers):
http://www.ralinktech.com.tw/data/dr...2008_03_13.dmg
The card works like a charm and it's a definite improvement boost especially if you have a N router availiable.