A few years ago, on a Christmas break, I decided to learn how to create balloon animals. It made me some money during undergrad, in addition to being a fairly random party trick.
My skills are a bit rusty, but Larry Moss and Kate Cheatle are all-pro. Catherine Stratton made the duo the subject of her recent film, The Fine Art of Folding Air. They also run a wonderfully titled business, Airigami, whose portfolio you can view here.