Who said Elf on the Shelf was strictly for kids? Grown-ups can get in on the action, too, with the Newbury Street League’s own Elf Challenge, taking place up and down the renowned retail district through December 19. More than two dozen shops participate in this whimsical scavenger hunt in which shoppers take pictures of strategically placed elf dolls and share them on social media (Instagram, Facebook and Twitter) along with the tag #NewburyStreetElf. Every Friday of the challenge, the most popular and creative posts are chosen as the winners of a Newbury Street shopping spree in the form of a bag of gift cards. That’s an early Christmas present sure to be on anyone’s list. Visit newburystreetleague.org for details.