My husband and I will be coming to Oahu for the first time on Aug. 11th, staying 6 nights before flying to Kauai. I'm a big penny pincher and am wondering about the different attraction savings you can find at the booklets they have available in airports vs. buying a Happenings entertainment book, Groupons, Living Social, etc. I'd love some actual examples from the airport booklets and Happenings if you could. I'm mainly interested in savings on attractions, boat rides and other fun activities, not restaurants since we'll be renting a place with a kitchen. If the savings aren't significant enough from other sources, I'm planning on buying a 3-Day Go Oahu card through Costco although that will be a hassle since they only sell e-vouchers that you have to exchange for the actual card once you get to Oahu. Then there's no guarantee that the things that require reservations like the catamaran cruise isn't already sold out. Thanks for your help.