February 8, 2012 barackobama: think-progress: Demonstrating: The EXTREME marshmallow cannon! (Pro tip: Want to be invited to the White House? Be a 14 year old who clearly designed the best invention ever). Photo of the day. Edit Delete Tags Autopost on tumblr http://keropla.tumblr.com/post/17255458195/barackobama-think-progress-demonst...