Mobile Broadband Card for Powerbook

I have seen these mobile broadband cards (PCMCIA slot card I think) offered by Verizon, Sprint and Cingular, but so far all the research I have found on the internet for each say that the minimum requirements for each is Windows XP. Does anyone know if these cards can be used on a Powerbook G4 strictly running OS or if there is a mobile broadband card out there that is compatible for Mac OS.
Thanks.

Mike

I forget the website out there where I got mine but dig a little deeper and you'll find it. Chances are someone from here will let you know. I bought a Sprint one from them and it worked flawlessly and it was added to my original sprint account. In fact, now i'm stuck with it and it's of no use to me because i have a MBP now that doesn't support that size card. Any suggestions anyone?