would be the ability to pause conversations while they were going on, so you could think about what you were going to say. I feel like most people would be about 60 percent wittier and kinder if they just had an extra second or two to think before they spoke. I know I would.
This is actually one of the reasons I like talking over instant messaging. Stopping for 30 seconds mid-conversation and staring blankly into space is seen as weird at best; over IM, that’s basically status quo.