The 3D internet (aka Second Life for the masses)
Since Linden Labs decided to open source their viewer a few years ago, a group of enthusiasts have taken it upon themselves to create an open source version of the Second Life virtual world server.
The Archimedes Death Ray!
The smart guys at MIT University have replicated the legendary Archimedes Death Ray.
Legend has it, Archimedes (a REALLY smart guy) used the rays of the sun to burn Roman ships way back in 212 BC. You can read more about it here