Android hackers have succeeded in unlocking the Motorola Photon 4G bootloader using the methods they first figured out for the Atrix 4G. Like most hacks of this nature, you're going to have to read the directions and understand everything before you jump in, and you'll need a bit of working knowledge of the standard fastboot procedures. Because it's a Motorola phone, you're also going to need to know how to use RSDLite. The good news is that the instructions are laid out nicely and it shouldn't be much of an issue once you get everything assembled.
The biggest thing to remember here, is that this is for the Photon only. Don't go trying it on your Droid 3, or you'll likely be in for an ugly surprise. With all that out of the way, head over to the source link and get started. Let the games begin!