Double the efficiency, double the smell.
Deviant Artist Midnight Angel put together an arm blade stylized after the ones used in the Assassin's Creed video game series. Using a drawer opening mechanism, a spring for a screen door, and a throwing knife, the weapon works surprisingly smoothly. The full instructions are on Angel's page, and you can see it in action below.
3 U Penn students developed the µWave (microwave, get it?), an Arduino based kitchen hack that plays Youtube videos while you wait for noms. Once you set the cooking time the program goes to Youtube and finds a highly-rated video for the exact length. Read more about it at the project's website.