Many things come and go in New York City: tourists, scaffolding, frozen yogurt shops. Now retail has joined the trend with a new kind of store: the pop-up—small, temporary venues that open spontaneously, close just as quickly and carry specialty items you might not find elsewhere. Sometimes the pop-ups are backed by major companies looking to promote new products; other times smaller merchants or online retailers test them out as a way to gain sales and exposure while avoiding the burdens of long-term leasing. And for the shopper, pop-up stores can offer the thrill of snapping up that special gift that no one else will find. While everybody else ends up combing the usual chains, you are well on your way to being dubbed the best gift-giver at the annual Secret Santa. Besides, with the store gone, there's no need to bother with a gift receipt.