I've got an iPhone 3G that runs unbearably slow on 4.01. I'm also unlocked to T-Mobile, which means that I know I can't run redsn0w as I'll lose my unlock when the official update updates my baseband. I see that PwnageTool can update a 3GS with the old bootrom to 4.1 jailbroken (source: http://www.redmondpie.com/how-to-jailbreak-iphone-3gs-on-ios-4.1-with-pwnagetool-guide/ ), and if PwnageTool works as I remember it, you can prevent the baseband update from occurring. However, I can't find any documentation as to whether or not this special version of PwnageTool works for an iPhone 3G; it only references iPhone 3GS w/old baseband. Any thoughts as to whether this version of PwnageTool can allow me to get to 4.1 while preserving my unlock on a 3G, not 3GS?