GEORGE Hamilton walked into a Cadillac dealership when he arrived in Hollywood a million years ago, and drove off in a free car. (The convertible so impressed a studio mogul, he was then given a contract.) Now the super-tanned actor will put those con-artist skills to work in a reality show, "Don't Mind If I Do," which has sparked a net work bidding war. "The show has George betting $2 million that he can go anywhere in the world, traveling and partying without spending a penny," said one insider. "Over a 30-day period, contestants will challenge him with locations and events to attend . . . if anyone can be the world's guest, it's George!"