Knock knock. Who’s there? It’s the end of this old-fashioned joke format. You see, with a Ring 2 video doorbell (£179) stuck to the front of your gaff you’ll never have to ask who’s there again, you can just fire up the app and see for yourself. You can still enquire as to their identity via its built-in speaker if you really want to, or you could tell your visitor about how this new version of the smart ding-donger has a removable battery, which means you don’t need to detach the whole thing when it needs recharging, and that its night vision skills have been improved. Not sure how many laughs you’ll get though.