Want to attend a bread-making workshop in San Francisco? Or spend a long weekend in Atlanta watching the Final Four and the Masters practice round? Whatever your pleasure, these slick sites allow you to create bespoke vacations by clicking on destination and activity boxes that call to mind the virtual storefronts of sites like Gilt and Rue La La. Some experiences are the centerpiece of travel packages that include hotel rooms, meals and airport transfers (usually not flights). Other experiences are sold separately. Most activities have some sort of exclusive element or are limited to small groups. The sites, while prettier than their predecessors, are still in their infancy so the inventory is not as vast as that of an established trip-planning site like Viator.com. And some experiences, like visiting the New England Aquarium, can be arranged on your own (though you might miss out on perks like skipping to the head of the line). That said, most of the trips on the sites appear to be priced fairly, and are ideal for travelers who want to anchor their vacation with activities. Even if you don’t use the Web sites to book a trip, you can browse them like magazines to help you decide where to go and what to do when you’re there. Below is a guide to the newcomers.