Last week, Royal Caribbean announced that its newest ship Project Genesis, to be delivered in 2009, will feature a replica of New York's Central Park.

And I thought: Uh oh! I mean, you know how cruise lines all try to outdo each other.

Here are some other announcements we may soon be hearing:

Holland America's new ship, the Neverdam, will feature a replica of the Grand Canyon. Sure, other ships give you rock climbing, we give you mule riding.

Disney Cruise Line's new ship, the Apotheosis, will come complete with a to-scale model of the Amazonian rain forest.

And Carnival's new ship, the Satisfaction, will give passengers the thrill of trekking through a 10,000 acre facsimile of the Australian Outback.

Happy Earth Day, everyone!