Hey, now you can mess up your next trade show too. This trick isn’t quite as bad as it doesn’t turn the TV’s off, it just makes the remote controls useless, which could also be considered worse.
In fact it doesn’t just jam the IR signals from your TV remote, but “most infrared signals” are jammed. So, this combined with a TV-B-Gone could actually cause even more havoc.
I presume it requires batteries, but the IR blaster that likely screws things up seems to be on the top, so you apparently don’t even have to aim it, just flip it on, make sure its within line of sight of all devices and remotes, and you are good to go. If you want one, they are about $10 each.