Ad of the Day: Robert Downey Jr. Surprises a 7-Year-Old With a Bionic 'Iron Man' Arm

Great spot for Microsoft's Collective Project

There are good ways to use your megafame, and bad ways to use your megafame. Robert Downey Jr. has happened upon one of the best ways to use his—by drawing attention to Limbitless, a company that makes 3-D-printed prostheses, and the recipient of one, a 7-year-old named Alex who really likes superheroes.