It's pretty disheartening to get an awesome new phone only to realize the bootloader's locked down tight. That's means no custom recovery, no ROMs, no custom kernels, no... anything fun. Until, of course, some dedicated developers get ahold of the device in question and bend it to their will. That's exactly what Project FreeGee has done for both the Sprint and AT&T variants of the LG Optimus G.
The tool essentially unlocks the bootloader of both devices, allowing a custom recovery - and eventually, custom ROMs - to be flashed.