Update iPhone 2g without sim card?

[CeeP]

Hi guys, I've had a 3gs for awhile now and had my 2g just sitting around. I wanted to give it to my mom so she could use it as a ipod, but when I tried to restore/update it, iTunes requires a sim card.
Is there a way I can update it without a sim card or do I have to put mine in? If I activate it with my sim card, will it screw up my 3gs?

Thanks,
Chris

 

[Applejuiced]

You can use redsnow or blackrain to hactivate it and it will let you into the homescreen.