Though it's had the record taken away since it first opened, AT&T Stadium, where the Dallas Cowboys play football, once boasted the world's largest HDTV screen. At 70 feet high and 160 feet wide, its scale is utterly mind-blowing. So of course Conan O'Brien used it to play video games.

One of the most startling revelations in this video is that the immense screen is actually turned on and off using the clapper. It makes sense given how easy it would be to lose the remote in that giant stadium, and who wants to constantly have to fetch a 70-foot ladder to reach the power button? But how they get 80,000 fans to refrain from clapping during a game so the screen doesn't constantly turn on and off is what's most impressive here. [YouTube via Tastefully Offensive]