Car / Taxi / Bus, Oahu
Rent a Jeep . . . I was worried about being able to rent a jeep because some of the chain rental agencies said that they were sold out. I did pre-book my jeep before I got to the Island but I did find out that there are many Jeep/car rental places around the hotels that have a wide variety of jeeps/cars available.
Rent a car. The island is easy to navigate and has good roads all around the island. Unless you want to sit on Waikiki the whole time a car is the way to go.