Railgun Rising

Remember in Transformers 2 when a Navy railgun knocks out one of the baddie robots? Well we have that and it works - er, the railgun, that is.

A railgun is an electromagnetic cannon that fires a solid projectile at ludicrous speeds at the target, where the huge amount of energy expended does the destructive work. We have the technology, it works, and it is being honed for battlefield use.
The Navy developed the railgun as a potent offensive weapon to blow holes in enemy ships, destroy tanks and level terrorist camps. The weapon system has the attention of top Pentagon officials also interested in its potential to knock enemy missiles out of the sky more inexpensively and in greater numbers than current missile-defense systems—perhaps within a decade.
Wall Street Journal