Logically, that sounds like a good plan. It would be a good idea to assure yourself of a way to keep off the cellular network. I would guess they put you on the pay-as-you-go for data, to be avoided unless you are wealthy. Through an error later corrected, I had a light month of 35100 kilobytes for which I was billed $520(US).

My use of the 6600 is very low level, so I have never had the device automatically connect to a network without my knowledge.

I'm having fair luck with the Socket card except that there's something funny with the driver load involving other low-level apps like ActiveSync or bluetooth. I've learned to deal with it, though.

Enjoy!