Yeah would be cool to program it to open/lock doors too. "I'm sorry dave, I'm afraid I can't do that" "But I need to get to work, unlock the front door!".
One of these days I actually want to experiment with some kind of custom speech recognition, I don't actually trust stuff like the echo or pretty much any consumer product, but something that runs soley on my home server would be fun. In general it would just be pre programmed commands, but could add some AI to it too. At most it would just be something to impress friends though.
I have been brainstorming my home automation system though, my current setup is not greatly modular and is already a mess of wires. I was going for using rackmount space, but something like that is really more well suited in a nema cabinet with din rails.