Why is my iguana so aggresive and how do i tame him?

Ever since i got Petey in January 2006 he has been real aggresive with me handling him. Every time I reach into his cage he jumps off of his branch and thrashes around the cage banging his head on the gl walls of the 40 gallon aquarium. I am looking into building him a new cage but i dont believe the cage has anything to do with his problem...I need help!!