I stumbled across a USB device that accepts a PCMCIA high speed data card (EVDO). This looks like an excellent solution for switching to a MacBook Pro and still being able to use my EVDO card. The problems are: 1) it isn’t shipping, yet, 2) they have no Mac drivers, and 3) it doesn’t list my card, the Sierra Wireless AirCard 580 as compatible. I’ve sent them email to see if they’d be interested in having me write a Mac driver. I’ll cross my fingers, but won’t count my chickens before they hatch.