Switching back and forth between 2g and 3g?

[NJIPhone]

I just bought a really clean 2g at a couldn't pass up price, I figured, worst case, it would be a good, cheap spare should my 3g be lost or damaged. Anyway, I thought I could just pop my sim card in and use the 2g without anything else being done. After installing the card it wanted to be connected to itunes which then wanted to activate it like a new phone, prompting menus that called for picking rates, plans, etc. I canceled out, put the sim back in my 3g and decided to seek some help.
Any ideas?

 

[APPCRITICal]

I would try updating the 2g with no sim in it. That was the old way for activating an iphone when you bought it. If you update the software it may work the newer way.

Good Luck

 

[NJIPhone]

It appears I'm pretty screwed here. The phone is locked at the emergency call only screen and it appears the only way to activate it is to put service on it, which I don't want to do. I even tried putting a deactivated sim card in but no joy. ANy ideas?