Thanks for the info. We will be staying on the North Shore of Maui near Napili. Yea restaurant ideas would be fantastic.Do Maui Downhill - it is a bike ride from the top of the Volcano to the sea (10K feet). My wife and I did it when we were out there and it is a blast! They bring you up for sunrise over the crater and you stop for lunch on the way down...well worth the time and money!
Here is a link - http://www.mauidownhill.com/mauibiketours/summitsunrise.html
The road to Hana is a ride up the twisty coast of HI...you go past a bunch of waterfalls, a black sand beach...etc.
link - http://www.mauiinformationguide.com/road-to-hana.php
We went snorkeling and sport fishing too...all great!
What part of the island are you staying? We stayed in Wailea at the Fairmont Kea Lani -- great area and great hotel. Let me know and I can track down a few of the restaurants that we liked...
Never went to Oahu...went to Maui, Lanai and Kawaii...definitely go see the monument in the harbor!!