Here’s a twofer: A great idea, and a video for said idea made by a great filmmaker. The former, Airbnb, is a beautifully designed service for finding single rooms or apartments to rent worldwide, and the latter, Adam Lisagor, is a charismatic gentleman making increasingly brilliant promotional spots for a variety of apps and sites, including the particularly exciting Square.
Oh, and the best thing about Airbnb? Dedicated categories for treehouses and castles. Incredible.