Daniel Ballou of Ballou Projects has this gallery of images for the Who's There Chair, a chair specifically designed to let you 'lock' any door Hollywood-movie style.
In the movies, jamming a chair under the doorknob can keep a threat away. That idea seldom works in reality. This chair plays on that Hollywood icon of defense, while making it functional. The back structure is steel and has leveling feet (like an extension ladder). A notch in the backrest is at the perfect height to interface with a doorknob, and rubber grips on the feet keep it in place.
Daniel is actually quite a creative mastermind: check out some of his other projects.
|C-pump: Single-Handed Soap-Dispenser|
|Letterpress Perpetual Calendar|
|iKettle: WiFi-Enabled, Smartphone Controlled Kettle|
|Loud Bicycle: Car Horns for Cyclists|
|MaKey MaKey: Turn Anything into a Keyboard, Even Your Kids|
|“Both spacecraft are still operational when they reached interstellar space.”|
|"Free apps make money by selling your personal data."|
|CaptchaTweet: Write Tweets in Captcha Form|
|“We’ve received requests to add some artificial noise to the buses so that people can hear them.”|
|How to Avoid Jury Duty|
|“Initial riders may be more comfortable getting into a car with a human in the driver seat.”|
|The (Very Scary) People of Public Transit|
|The Festive Funk Machine: Click to Make Your Own Festive Music|
|Naked Preacher Lady [NSFW]|
|“Can you replace the spring of a pogo stick with repelling magnets?”|