maya already has that out of the box doesnt it ? those 2 fields on top of the uv editor they are set to absolute mode by default but this little 0.0 red arrow button 2 icons to the right toggles it to relative mode !
So i've been working on this dude in the last 2 months for a CG Workshop course i attended as a student, and finally yesterday i think the journey came to an end. Specs: 24k polys + 2 x 2048 textures.