Verizon Wireless service

Yes Glenn, that cellular wireless service that you are trying is CDMA2000. (Probably only 1X though). Stephen Den Beste will no doubt be happy.

I can't imagine there is any way it will interfere with WiFi. WiFi operates on 2.4 GHz or (not often just yet, but probably an awful lot in future) 5MHz. Verizon's wireless service is on 800MHz or 1.9Ghz. The frequencies are completely different.

Update: If I had really wanted to cover all my options, I could have bought my laptop with 802.11a/b/g, a GPRS modem (ie a cellular modem running over GSM networks), Bluetooth, and IrDA infrared. The version I bought has 802.11b/g and IrDA only. That's enough for me now. (Bluetooth likely does reduce the performance of WiFi if used at the same time, as it uses the same 2.4GHz frequency band).