I flashed with blackra1n (whoops)
The iphone is running with or without a sim card in it both just fine. But the sim card is from some old nokia phone. At least the iphone recognizes it.

Can i just get a gophone and activate it?

How do I make sure it's not sim locked to the go phone?
(i read some thread about getting two go phones and activating one sim in the other, the swapping it to the iphone?)