but light speed has nothing to do with control of light. unless of course you're not talking about travelling at light speed but actually controlling the speed at which light travels
well, partially, but i don't wanna go around drawing circles on stuff. it'd b great for magic shows, and making people think u have bottemless pockets =)
Time control would b cool, like Hiro in Heroes. but sum1's already said that.
i'd probably go for materialisation. make/assemble anything with just a thought, only limited by your imagination. the physics will take care of itself =)