Fractional ownership is very rapidly becoming a popular alternative to single ownership of vacation property.
How it works:
A condominium or home is divided into "shares" (usually from 4 to 10). Each buyer acquires fee simple title to his/her share of the property and gets to use that property according to a predetermined (and adjustable) schedule.
Membership in the golf club or the spa, ski passes, and a myriad of other privileges often go along with ownership. It's like becoming a member of a club.
The advantage is that you get all the perks of membership, plus the re-saleable ownership of a portion of an expensive piece of property, for a fraction of the cost.
The disadvantage is that you do not own your unit entirely and do not have total say in what can be done with it - only during your weeks of ownership. Furthermore, since fractional ownership is a relatively new concept, the resale value of your share is not entirely certain, although many have already been re-sold at handsome profits.