Proposed in 2006, the proposed underwater hotel for Fiji known as Poseidon Resort Mystery Island has released new designs. Although it is still seeking funding to support the development you can now start saving your pennies for this vacation paradise. They estimate it will cost $30,000/couple for a week.
So cool, as long as you don't mind being underwater. :) Aquarium wall: Dubai's underwater hotel. The hotel's suites provide views from both the bedroom and the bathroom windows into a lagoon filled with 65000 marine animals. AMAZING! - I NEED TO GO HERE!!