Here is some info I found that may be of use.
Originally Apple Lombards and Pismos only had one option for wireless networking, and that was the original Apple airport card that gave 802.11b (meaning 11 Mbps) which was great back in 1999, but not today! The card has
issues connecting to the newer, faster networks of today, and can be difficult to connect with. The original Airport card is
overpriced now a days, and outdated to be honest.
So, how do you get Apple Airport Extreme speeds, for the 802.11g wireless networks (54Mbps) on a Powerbook G3 in Mac OS X? Is it an Apple secret? Read on...
The answer is with Belkin, and their Wireless PCMCIA cards, specifically the Belkin 802.11g wireless PCMCIA card, model # F5D7010.
You must get revision 1315 or revision 1112, as they have been tested to work (heck mine works, rev. 1315). If an auction does not specify the version, then ask the seller to specify.
Belkin rev.3000 does not work, so make sure you get the right version.
Why do these Windows based PCMCIA wireless cards work in an Apple when it is not advertised anywhere on the box or on the manufacturers website? They work because they use the Broadcom chipsets for Mac G3/G4 laptops.
The PCMCIA cards just plug right into the Powerbook G3 PC card slot on the side and Mac OS X recognizes them immediately. If you want drivers do a Google search on "Belkin F5D7010 Mac OS X drivers" to find them. The only downside is that the card sticks out of the side of the Powerbook an inch... but hey, now you've got 802.11g (54 Mbps)!
There is one other PCMCIA card that plugs right in, the Asante AL5403-XG. Keep an eye out for either the Asante or Belkin, I have seen some on eBay as low as $0.99.