http://cache.gizmodo.com/assets/imag...x_IMG_4739.jpg
iPhone 3GSes now ship with a chained-down boot ROM, intended to thwart jailbreakers at a fundamental level. It's already been cracked. But for what it's worth (seriously, what?), it has made life outside the App Store a little less convenient.
http://gizmodo.com/5382620/apples-ja...-totally-arent