In short: Sonnet Aria Extreme Airport Network Adapter - G54-CB took over from Airport Card which would not work on my Titanium 15" Powerbook. Insert into PC slot, boot up, and it works like a charm! Details: My Airport card in my Titanium 15" Powerbook no longer would connect to my home wireless network, using a Linksys 802.11b router. I swapped the Airport card for one that I knew worked. Still would not connect, though the Powerbook had connected in the past with earlier versions of OS X (can't recall how far back before it stopped working). I am running Tiger 10.4.3. Also, did the latest Airport update. Then, thinking it might be the router, I replaced it with a Linksys Wireless G (802.11g), router, and it still did not work. (A wireless-connected HP printer worked with both routers, though). So, I did some fancy Googling and located the Sonnet Aria Extreme Airport Network Adapter - G54-CB, which is claimed to work in 15" Ti-Books (Titanium Powerbooks). I inserted it in the PC slot, booted up, and I was connected immediately! Works fine. The lowest price I found, by far, was at Buy.com: $58 with free shipping: http://www.buy.com/prod/Sonnet_Aria_Extreme_Airport_Network_Adapter/q/loc/101/10363721.html --Steve