How to Unlock an iOS 4.2.1 / 4.1 iPhone 3G / 3GS by flashing the baseband to 6.15

Unlocking the iPhone can save you a ton of money and irritation by getting you off AT&T and onto a better service provider. One way to do that is flashing the baseband to one that works on the iPad, and this video will show you how to do using Redsn0w that, provided you're working from a iOS 4.2.1 / 4.1 equipped iPhone 3G / 3GS on baseband 5.14 or 5.15 (about to be 6.15 when you're done).

click here for a written version of the tutorial.