With land getting so crowded, the age-old fantasy of sea-based living is becoming reality.

The idea isn’t so far-fetched. As Earth gets increasingly crowded and polluted, some 225 million square miles of prime real estate representing 71 percent of the planet’s surface is largely unused. It’s remarkable considering the oceans promise plenty of living space, fresh seafood, entertainment, and desalinized water. Surely, technology can make this happen.

The most tangible signs are two altered versions of GM’s Hotel Atlantis, at least one of which could be open for business next year.

The first is Hydropolis, a $500 million-plus, 220-room hotel under development near Dubai in the Persian Gulf. Billed as the world’s first underwater hotel, the Hydropolis will be located, if all goes according to plan, 60 feet below sea level and cost $1,500 a night. Among other amenities, the Hydropolis will also feature a missile defense system to guard against terrorists, a shopping mall, and three bars.

Then there’s Poseidon Mystery Island, a $200 million development off the coast of Fiji. When it opens in mid-2008, the hotel will be much smaller than Hydropolis and almost twice as expensive to visit. But it does boast something you don’t get in Dubai: 24-hour views of one of the world’s liveliest coral reefs.

Whether these two projects ultimately swim remains to be seen. The engineering challenges aside, there are plenty of unanswered questions about the environmental impact of these underwater havens. And while Poseidon is taking reservations, construction delays at the Hydropolis will likely extend its scheduled 2008 opening.

CNN Money

The popular website YouTube.com, usually associated with outlandish and wacky videos, is making the ins in the real estate market.

In The Netherlands, Elkhuistekoop.nl (Every House for Sale) encourages people to fill in an online form if they’ve spotted the house of their dreams and it isn’t yet for sale. Elkhuistekoop then contacts the property’s owners to find out whether they have short or long term intentions to sell. If an owner’s dormant desire to sell is awakened, Elkhuistekoop hooks up the buying party with a real estate agent, and the agent pays a finder’s fee. The service is free for house seekers. Elkhuistekoop is definitely less elaborate than Igglo, which took pictures of every building in Helsinki. On the other hand, it offers consumers an easy and discreet alternative to knocking on dream house doors themselves.

In the U.S., online real estate service Zillow lets home owners take the initiative, by allowing them to set a Make Me Move price without actually putting their house on the market. Once owners set a price (”that magical number you just can’t refuse”), potential buyers can contact them anonymously via email. It’s then up to the owner to decide whether they really want to sell.

Zillow identifies a few different reasons for owners to use Make Me Move. If they’re thinking about selling in the near future, the service helps to start gathering interest. Or they may have long term plans to sell, but could be motivated to do so sooner if the right offer comes along. Zillow launched Make Me Move a week ago, and already has 3,682 prosperities listed with MMM prices.

springwise.com

Health officials in a handful of states are warning home-buyers and renters to check an online database of busted “meth houses” to make sure they don’t move into a contaminated former drug lab.

The state estimates cleanup costs of $15,000 to $30,000 to decontaminate a 2,000-square-foot house.

Known for its high rate of addiction and severe side effects, which include rotten teeth and increased risk of heart, lung and liver disease, meth easily can be made with over-the-counter cold medication, household chemicals and a hot plate or burner. Every pound of meth cooked results in up to five to seven pounds of toxic chemical wastes that pose serious health and environmental hazards, according to the U.S. Drug Enforcement Agency (DEA).

It’s illegal in 12 states (Arkansas, Arizona, California, Colorado, Idaho, Minnesota, Michigan, Nebraska, North Carolina, Oregon, Tennessee and Washington) for anyone to live in a former meth house before it’s been decontaminated, according to the National Alliance for Model State Drug Laws, a congressionally funded nonprofit that helps states set drug laws.

Here are a few databases for Idaho, Montana, Oregon, Washington.