See the world without leaving your front porch on the Four Seasons' first residential cruise ship. The Four Seasons, set to sail in fall 2007, began selling out—sight unseen—before an official announcement was even made. The 100 luxury apartments range in size from 1,336 to 3,434 square feet and have seven floor plans, with three design schemes. Along with ever-changing views, tenants will also have access to the hotel group's indulgent amenities— spa treatments, personal chefs—as well as the services of a travel coordinator for voyages in such ports of call as Alaska, Venezuela, even Senegal.; from $400,000 for a one-month time-share for 50 years. —SARAH FORREST