A long time ago there was a post about Emotes. This suggestion builds on that: An element (existing or new) that can detect when an emote has occurred within a definable area/location.
But what use could such a detector have? Sure, saluting a door to have it open is funny the first few times but let's take it a bit further. How about showing a warning on a screen when someone gestures rudely? Or using a combination of gestures to open a container? Or a drink pops up at the bar when someone waves? Or making a in-game game called Emote Emote Revolution? With LUA the possibilities are limited only by your imagination.
DU you have more suggestions of what could be made with an emote detector?