Hi to all those Oahu experts out there! Some of the hotels that have been suggested here are: Aston Waikiki Beach Tower, Outrigger Reef on the Beach, Halekulani, Kahala Mandarin, and the Otani Kaimana. Now, which of these is on the beach and in the middle of everything? Our hope is to spend three hectic days in Oahu before our one week in Kauai. We would love it if we did not have to rent a car in Oahu.
Thank you!

"Right in the middle of everything" :

Outrigger Waikiki (ground zero, LOL)
Sheraton Waikiki
Sheraton Royal Hawaiian
Sheraton Moana Surfrider.

The Halekulani is right on the beach and in the middle of everything. I *think* the Outrigger Reef is right next door, also on the beach and in the middle of everything. Both are close to the Sheratons that the other poster mentions.

You don't need a car for Waikiki - but if you want to see other (less crowded, prettier, more interesting) areas of Oahu (such as the North Shore, Kailua, Hanauma Bay, Pearl Harbor, etc.) it will be helpful to have a car to do some exploring.

At travelocity it is possible to search for hotels and have them shown on the map - this may be an easy way for you to get a quick look at where each hotel is located.

I agree with scigirl that having a car will make it much easier to see the sights on Oahu outside of Waikiki. And trust me and many other Fodorites on this: there is much more to Oahu than Waikiki.

BTW, if you are considering the Kahala Mandarin Oriental Hawaii Hotel, it is not near Waikiki or the "middle of everything." Rather, it is past Diamond Head. But DO go there for dinner one night. The restaurant there (Hoku's) is exquisite. Out of all the fine dining in Oahu and the Big Island that I did on my trip there last year, dinner there was the most memorable.

the Aston Waikiki Beach Tower is across the street from the beach. The Halekulani is on the water, but i believe there is a retaining wall in that spot, not a sandy beach. of course, it's only a short walk from there to the sand. The Outrigger Reef is on one side of the Halekulani, the Sheraton on the other, and both are directly on the beach. The new Otani Kaimana is not in the middle of everything but is separated from the main part of Waikiki by a park.

You can enjoy Waikiki on foot easily, and you can get to sites of interest in Honolulu by taxi and bus. You might want to rent a car for one day to drive around the island to see the rest of O'ahu.

Outrigger Reef on the Beach is definitely "in the middle of everything", and it's right on the beach. Ditto it's sister, Outrigger Waikiki on the Beach, home of the legendary "Duke's".
Halekulani is right on Waikiki too, but it's small, elegant, refined and has a calmer, more dignified feel to it. If you want "three hectic days on the beach" choose one of the two Outrigger hotels. Very lively, very busy and lots of fun.

The Hilton Hawaiian Village has everything you're looking for. It's a beautiful property with great amenities. Enjoy.