House Without a Key?
 

Ive read about this place many times on the forum, so now I want to go. Where is it exactly? What's it about?

Beautiful restaurant with wonderful food and great ambience.

As IslandMom pointed out, it is at at the Halekulani, which is situated between the Sheraton and the Outrigger Reef. Turn towards the beach on Kalakaua Avenue on Lewers Street and the hotel is at the very end of the street.

Make sure to go for the sunset and watch Kano'e Miller dance the hula to a Hawaiian music trio.

House Without a Key is located ground floor oceanfront in the Halekulani hotel. You can have drinks on the patio or a light dinner (I believe there's a menu on the Halekulani site). Hawaiian music and hula every evening from 6:00 to 8:30ish. Wonderful ambience and our favorite place for sunset and drinks in Waikiki. They also serve breakfast and afternoon tea, but we prefer to come in the late afternoon/early evening.