Video games have come a long way since Pong.Many kids — and more than a few adults — entertain themselves for hours by battling invading aliens, pretending to be rock stars or gunning the throttle of a dirt bike to edge out a virtual competitor at the finish line.The increasingly realistic and complex virtual playgrounds that are now standard in many homes might also have another, unintended, benefit: scientific research.Some see the interactive fantasy lands as a new frontier for behavioral, political and economic research. Modern video games could provide a valuable portal for social scientists to expand their studies, or even to conduct research that would be almost impossible in the real world.Popular interactive games such as “Second Life” and “World of Warcraft” (see figure) and others offer enterprising researchers a virtual laboratory. Such investigations would be relatively inexpensive and easily accessible. And there are potentially thousands of research subjects, who would remain anonymous while participating through a host of characters. Studies could range from experiments in social psychology to the examination of social networks and economic systems. An analysis of virtual research was published in the July 27 issue of Science.But there are, of course, a number of ethical considerations. Online research could require the scrutiny of review boards. And it is debatable whether such virtual worlds are public space or private places. Would it be the right thing to notify possibly thousands of people scattered around the world that the online actions of the characters they are controlling are under analysis?