Don't know if this is feasible for you, but one idea is to take a one-hour helicopter tour of Maui while you are waiting. It is spectacular; really something to remember. You will see absolutely pristine rain forest and gorgeous waterfalls. It will probably be about $150/person, though. If you decide to do it, the helicopter terminal is about five minutes away from the main airport, and Blue Hawaii helicopters is a great company.

Otherwise, there is some sort of aquarium about 15-20 minutes away by car that is supposed to be interesting. I haven't been there.