I just love how people have this amazing memory for a very unique situation (the 5.08 bootloader ----VERY RARE, and the iphone 3g combo that produced a method for downgrading) that occurred almost 3 years ago and still drudge this up every time someone talks about downgrading, even though it doesn't apply to their newer iphone model.
People: forget that you can do this already! It hasn't applied to iphone owners for years now. Even when it did, it was for a very small group of iphones. I purchased my 3g within a couple days of launch at an apple store and it already had the 5.09 bootloader.