Dear Titanistas! Thanks so much for all the input so far and sorry about the confusion. Yes, I was referring to a PCMCIA card for the 400 Mhz Powerbook. The Airport Extreme Card has specs that don't match the possibilities of the 400 Mhz TiBook. Read this document by Apple: http://docs.info.apple.com/article.html?artnum=107440 Right now I'm looking for more info on the Buffalo card as is suggested in this group. Their Wifi 54G router also seems to work with Apple systems. Anybody any experience with this router? The price difference with the Airport Base Station is considerable. I'll update you on my experiences... thanks to all, Bart Haensel, Amsterdam