Puerto Morelos, Mexico
For some travelers, itsy bitsy bikinis or revealing Speedos just don't cut it -- a vacation isn't a vacation without a little nudity. Luckily for them, these hotels are redefining casual dress with policies that let guests bare it all (or almost all). So take a peek -- a little voyeurism never hurt anyone. First up, Desire Resort and Spa. You'll find all sorts at this clothing-optional, couples-only resort, from older married couples, to young nudists, to swingers. One thing they all have in common: They like to get naked. The resort bills itself as "a place of freedom where fantasies become real," and these fantasies can become real all over the property -- the white-sand beach, the big pool, and especially the large Jacuzzi, which can get pretty X-rated towards the wee hours of the morning.