Hey guys, I haven't posted here forever. I used to be all over ipod touch jailbreaking in 2007/2008 but I've now had an unjailbroken iPhone 3G for 2 years and im about to sell it to buy the iPhone 4. On my 3G I am actually still running firmware 3.0.1 because a while back I did the ATT carrier hack from help.benm.at. and I have used the phone a lot for tethering to my MBP while commuting on the train. What I am wondering is if there is a way I can prepare my phone for a sale on craigslist while wiping my personal data but still preserving 3.0.1 and the tethering carrier hack. If so, how should I do this? Also, I am so out of it nowadays but is there a way to tether on the iPhone 4 without paying ATT? I am assuming it has to be jailbroken? Thanks!