Novatel used to manufacture a PCMCIA card called the Merlin. It's a CDMA 3G data card; it supports both 1xRTT and EVDO. The Merlin came in two brands, the S620 and the V620. S is for Sprint, and V is for Verizon. Other than that, the cards seem to be identical.
For some strange reason, Novatel doesn't want anyone to know the Hayes commands for running them. That means they're fairly difficult to use in Linux. You're going to get them for free, just for coming to this webpage. Lucky you!
I'm not going to tell you how to get it to work under Red Hat or Gentoo or Ubuntu or whatever, since I don't use any of those. I use a simple dial script with wvdial. It works for me. If you ask real nice, I'll give you a copy. Your software will be different, so I'm giving generic instructions. They may even work with Windows. I suppose that means that the title of this page is misleading; I don't care.
EVDO Only, No Roaming
To initialize the modem, use the init string AT Q0 V1 E1 S0=0 &C1 &D2 +FCLASS=0.
To get the modem to tell you the signal quality, use the string AT +CSQ. The first number will be (I belive) the RSSI, in dBm. The second number will be either 99 or not 99, but usually 99. I don't know what it's for.
Then, dial the data connection with AT D #777. Or, if you're given just a spot for a phone number, use