Although this has been acknowledged before (Star Trek inventing the future and all that), during the recent 50th Anniversary of Star Trek where many or all of the original episodes (remastered so they look nicer on today's televisions) were shown, I was moved by the earpieces they use, since they are like clunky Bluetooth earpieces. Here's a quick (and thus blurry) photo I grabbed off my TV with Spock in the foreground with his easily observable earpiece and Uhura in the background adjusting hers. Granted for TV such technologies would need to be easily observable by the audience, especially in the mid-1960s, today not so much since we actually have these things.
