Vacations with extended family are the biggest trend Virtuoso's network of 9,000 travel advisers have seen in years, according to Cain. That's because Baby Boomers are now grandparents who have the means, time and desire to take their families away on special trips.

There are a number of ways to do these multi-generational trips, from villa rentals in Europe to dude ranches out West to resorts in the Caribbean. But Cain said the easiest way is often through cruising, since many ships offer kids' programs, on-board babysitting and adjoining rooms, and are friendly to those who are less mobile. Trips that work best balance family togetherness with the freedom to do your own thing.