This was one of my favorite trips to date. My friend and her mother along with my mother and I spent about a week (overlapping a few days) in Waikiki. Since my dad travels a lot for work we stayed at the Hilton Hawaiian Village basically for free. We crammed a lot into one week. I purchased the Go Oahu card prior to our trip (I think about a month before). The card is ordinarily around $250 but they do a lot of sales. I booked it in advance so that I would have plenty of time to make reservations for the activities we wanted to do and see what the transportation options were. A lot of the attractions are free with the card but you have to find your own way there and that gets pretty pricey. When calling a few of the places, I discovered that several of them provide shuttle service for an additional (rather smallish) charge but that wasn't often publicized. I used this card for just about all of the activities I did on the trip and because we purchased a five day pass, I got to swim with the dolphins for free. Good deal!