If you have not found housing prior to arriving, or you want to wait till you are here, you might consider staying in a hostel or a hotel. Hotels.com features discount hotels throughout the state.

Discount Hotels Hawai’i features Waikiki hotels.

Hostels provide affordable housing, usually in a dorm setting with up to eight persons sharing a room. Here’s a list of hostel options.
Waikiki Beachside Hostel
Hokondo Hawaii Hostels Management Company