My husband and I are taking our 4 kids to Hawaii in April for the first time. We are going to Oahu and staying in the Waikiki area. Kids ages 23, 21, 18 & 13. Action is the word! Suggestions of things to do?

It's in Maui, but biking down Mt. Haleakala is loads of fun.
Helicoptering over the active volcano is also great, I have pictures of a lava stream overtaking a tree, street signs sticking up out of hardened lava.

Bring lots of money.

Surfing, kayaking, snorkeling, hike up Diamond Head.

And everyone should see the USS Arizona memorial at Pearl Harbor.

Deep Sea Fishing is some of the best in the world out of Oahu.

Free Fireworks on Friday nights at one of the hotels

Dole Plantation, Macadamia Nut Plantation, Dukes Seafood, hit the Bonzai Pipeline on the North Shore.

We stayed on Oahu and we also did a submarine tour off right off of Waikiki Beach near the Hilton Hotel. We did the Dole Plantation, a luau one night (that was awesome), toured thenorth shore. We went to the Pearl Harbor USS Arizona memorial, there is a national cemetary. We rented a car and for an island that is less than 50 miles across, we put almost 500 miles on it in 10 days. We had an awesome time. It as just my husband and myself and another couple, no children. Our timeshare had a private beach, so one day we just hung out there. We did find a tiny little restaurant near our timeshare that we had breakfast at the second day, it ended up we went there most days for breakfast. Food was awesome. It was like a place for 'the regulars'. One morning there was a Harley Davidson meeting, the parking lots was filled with bikes. We walked in to a crowd in their biker attire, looking like the tourists that we were, at first feeling kinda out of place, but everyone we came in contact was super nice. We went to a giant flea market at the Aloha Stadium. It was a great time. Hope you have fun!

+1 for visiting the Arizona Memorial. It was a weird feeling seeing someone with my family name listed there, even though I knew it wasn't a relative. (My grandfather served in Japan during the occupation.)

How can you be sure that it is not a long forgotten relative unless you have a more common last name like Roberts or something.

I used to live on Kauai, and have a ton of secret spots. But they aren't tourist-y so wouldn't have the fun things for family to do. They are mainly just nice hidden beaches. You will have a BLAST! I am jealous.

Stay away from Malaysian Airlines

What was Ken's last name?

as in "The Dread Pirate Roberts?" How cool...

One thing that you can do on Waikiki is take an outrigger canoe ride. The group helps paddle out and then the canoe rides a wave in towards shore like someone surfing. When we did it, we got a ride on three waves and someone takes pictures of the group as part of the package. I still use the picture of our family with Diamond Head in the background as the photo for the desktop on my computer.

Hawaii is one of the places I have no desire to visit

I totally agree with this. I don't see what the allure is. Fly half way across the world to experience one of the highest poverty levels, lowest education levels, and the weather that is available in several places on the mainland.

Great. No thanks.

My brother is stationed at Pearl Harbor and we visited last year. We did the submarine tour off of Wakiki, Dole Plantation, a luau (which wasn't as great as I thought it would be) and visited the Arizona Memorial (there is LOTS to do - plan for a whole day). We also drove around the island to see the North Shore. I felt like the prettiest beaches were on the east side of the Island. Becuase he is military we were able to go on the Air Force base for our "beach time", but the public beaches over on that side were beautiful, too. There were lots of hiking opportunities all over the island - get a guide book to find the one that best suits your group. And don't miss the Fine A$$ Chocolates over on the east side of the island. The name of the store and the candies are funny, but that chocolate is no joke! Have a great time!!

That actually sounds like something I'd like to try.

Where on the mainland can you get the same experiance as Hawaii?

I went to Islands of Maui and O'ahu. The weather was perfect everyday. Great food! Prices were higher, but not outrageous.

Great Golf, and best of all NO SNAKES!

Bayonne NJ

Pearl Habor was special for me since my Grandfather was there during the attack. Toured the Missouri, the Arizona, and then took a bus tour of the island. Visited the punch bowl crater.

Walked up to and through Diamond Head.

Really enjoyed it, may go back someday to see the main island, and have some friend who just moved to Maui.

Not a beach person, don't play golf, just not a place I want to go. I'd rather spend the same amount of money and go to Europe...i'll include Ireland because they have no snakes either. (and I have friends that own a B&B in Hawaii, so i have a free place to stay...no thanks, not my thing).

Adopt me so I can go.

Ireland is on my bucket list, too. Hawaii was just simply beautiful, as I am sure a Caribbean island trip would be. Not a beach guy either, other than taking in the scenery, if you know what I mean.

What kind of scenery would you expect on a beach in Hawaii?

I've been twice, and I'd go back in a heartbeat, if I got cheap airfare. I've never been to Oahu, so I can't help with the topic, but we've been to Lanai for a week and to Maui for two weeks. Maui is an incredible island. It's so lush on the northeast coast, but you can find a desert of black lava in the south.

Pearl Harbor for the Arizona memorial.
Aloha Stadium for the flea market. You can get all your touristy souvenirs cheaper there than the International Marketplace (which is in Waikiki, still worth a walk through though!).
Surfing, you can rent boards right on the beach in Waikiki. You could check with the hotel and see if they offer board rentals and lessons.
Go up to North Shore. Waves won't be huge in April, but still cool to see. Stop by Matsumoto for shave ice. Make sure you buy a pineapple from a roadside stand! Best pineapple on the island and they will cut it up for you right there.
Koa Pancake House in Kaneohe if you make it up that way. Or Wailana Café in Waikiki. Wonder if they still have all you can eat pancakes... Best deal in Waikiki! And they have an awesome coconut syrup!
Hike Diamondhead. Beautiful view from the top.
I personally would tour University of Hawaii at Manoa campus, but mostly because I graduated from there and would love to see it again! While you are up that way, you can hike Manoa Falls too.
I'm sure I'll think of more, but those are the big, have-to-do-touristy things I can think of.