I just learned about the Rock Islands of Palau:
The islands, between 250 to 300 in number according to different sources, with an aggregate area of 47 km² and a height up to 207 m, and are for the most part uninhabited, and are famous for their beaches, blue lagoons and the peculiar umbrella-like shapes of many of the islands themselves. The Rock Islands and the surrounding reefs make up Palau's popular tourist sites such as Blue Corner, Blue hole, German Chanel, Ngermeaus Island and the famed Jellyfish Lake
I'm not a scuba diver, but the uninhabited beaches and blue lagoons sound very interesting. The Wikipedia page is short and unreferenced. How could someone explore such a remote location? Helicopter? Boat rental? Local tours?
Note: The bounty will be awarded to the answer that has the most information on exploring the uninhabited islands themselves. I'd be especially interested in info about tours that actually take you on to explore the land of the best islands. Credit to Mark for at least a good start.