Don Howdeshell (who previously taught his daughter not to wake her parents up at an un-godly hour using a Pi) wanted to allow his wife to control the garage door from the Android tablet mounted in her car. So, he interfaced a Raspberry Pi with the mechanism and hey, presto, that is in fact what he managed to do. Read about the build on his blog.
Wesley Archer has taken an old Playstation console, a Raspberry Pi, a few other bits and some custom circuitry and created a retro gaming machine. He’s now blogged about it over at Pi Supply. Read more here.
PJ Evans was fortunate enough to find a cheap ZX Spectrum online and decided to resurrect it using a Raspberry Pi Model B+, an Arduino and some USB conversion circuitry. He is currently part-way through his build and is documenting it on his blog.