to move the objects pivot point hit the insert key then just move it to were you wish, and hit the insert key again 
um my uv map looks like that, the blue circle is one side of the tyre, and i just basically put the picture of the tyre in it, duplicated it and put it on the other side and the red is the part of the tyre i didnt care about. lol.
so yea im not exactly a role model
and may get shot by the pros for doing it this way
the more I Think I know about Maya the less I seem to know about it.
check me out
www.rm3d.co.uk