It should activate with your current info once you put the card in. I am actually going through this right now, but not with a V1 iPhone. I am exchanging my 8GB 3G for a 16GB 3g in an hour or so and I got a Treo 750 from a friend at work to use until AT&T can get me a new phone through DF (even though the Apple store across the street has plenty in stock!) I just put my SIM from my 3G in the Treo and it works just fine. I would doubt the V1 will work any differently, but it shouldn't hurt anything to try it out.
Do you have a data plan for the card itself? Before I bought my 881 USB 3G modem from them, I was going to look on eBay for the 881 and switch the sim into the modem from my iPhone when on the road and needed an internet connection.
I only worried about them catching on from the amount of data that would have been downloaded in bursts and didn't want to deal with any negatives from them.
I don't have a laptop aircard data plan. I know that if ATT catches on to me using my sim in another device, they may pop me with some fees.
I have heard of quite a few people doing what I'm doing without getting caught.
I believe that if you keep the data usage reasonable, it shouldn't be a problem. However keeping data usage down may be difficult. I was on FOX.com last night watching a full episode of House in HD. The 3g network was FAST!
If anyone wants to try this, let me know, I will try to dig up the connection parameters from my aircard. It took me several hours of research to find the correct connection settings.
swapping the sim is so good for going to bars. Just swap the sim get tanked and don't worry about dropping or breaking anything of value. Did it all last year in college. Never got a scratch on my iPhone.
The thing with swapping the iPhone 3G chip into a modem is that the imei number will change when you connect. I think AT&T could readily see that you are using a modem and not your phone. That's the only thing that held me back. Instead I pay the $60 a month for " unlimited " laptopconnect.