A Holiday Inn in New York City, with the help of master house-of-cards builder Bryan Berg, has built a guest house (lobby, bedroom, bathroom) out of 200,000 key cards. That even extends to the undoubtedly-painful key-card toilet paper.
Berg is the world-record holder of pretty much every house-of-cards award there is, and this hotel suite is his only full-size (meaning scaled to people size) project to date. It's not a functioning hotel room—we're pretty sure that toilet could actually handle the duties of a real toilet—but it'll stay constructed until the end of the weekend as a gallery or large-scale art piece. [Daily Mail, thanks Billy!]