If you think that Tsmuk's Banryu guard-dragon isn't quite old school enough for you, check out the new PatrolBot from ActivMedia Robotics, which looks like a 1980's interpretation of a 1950's sci-fi bot. Besides the usual security and surveillance stuff, the PatrolBot can do a bunch of other useful things like greet guests, lead building tours, and find out which parts of your office or home have crappy WiFi coverage. Starts at $30,000.