A Rail Gun -- Straight from Stargate Atlantis

Well, actually rail guns (magnetic projectile slingers) have been in development for decades. There was an installation at Eglin AFB that used to shoot slugs out over the Gulf of Mexico. This article (again from my growing favorite: Popular Mechanics) shows the future of these linear accelerators. Keep in mind that these things have other uses. Such as launching cargo from a base on the moon. See this Webpage...