Some Hawaiian wild horse links:
A two year old article about horses shot by a farmer.
An adorable picture of a wild colt.
Here is a short video of wild horses on the beach.
A Seattle PI article on horse getaways in Hawaii. The author rode a once wild horse at a dude ranch.
I looked up some info, and I think we might be able to afford a ride there. It's not quite as expensive as I remembered.