Hey everybody, i have a question about my jailbroken iphone.
Currently I am running 3.1.2 jailbroken with blackra1n untethered with modem firmware 05.11.07. My jailbreak works fine and i am running with my legit ATT sim card

I want to sell my phone after I get the iPhone 4. I would like to sell my 3GS unlocked and jailbroken because I think I can get more money for it with those mods made to it.

I am just looking for conformation that this works. I want to Restore my Iphone with 3.1.2, then run blackra1n to jailbreak and install cydia, rock, and sn0w, then sell it on ebay or something.

If I do this, will I have to activate my phone first with my legit att simcard, then take it out and put in a friends Tmobile to test? Or do I not need to activate the phone at all? If I do have to activate it with my SIM, will that leave any of my info on the phone when I sell it to a stranger? Also can I relock the phone if I end up not selling it on eBay, or do I not even need to bother?

Please help