I have been trying to figure this out all day but am making absolutely NO headway. My first go around I was told to update your iphone to current, download greenpois0n and follow directions. I did, Everything looked fine until I try to open the "loader" app, which did not do anything at all. No Cydia. After poking around forums and doing my own googling (extensive!!!) and was told to use pwnagetools in order to unlock the 4.2.8. Sounds good, except every link I have found for the pwnagetools download has been dead or 404ed! Now it seems that "redsn0w" is the only way to go, which I am waiting for the torrent to pick up and go. Is this a fools errand? Am I better off somehow "un-updating" the iPhone if even possible?