If you're prone to losing your keys and locking yourself out of the house when you get home, you'll want to pay attention to this brilliant home mod by YouTuber oggfaba. Using hardware and timber you can easily find at any home improvement megalopolis, they created a near-invisible secret door that perfectly blends in with the exterior of their house.
Of course, now that this video has been posted to YouTube, the door isn't exactly secret any more. So oggfaba integrated a remote-controlled deadbolt to keep it secure. But if you do as brilliant a job when you build your own, there's really no reason to lock it as long as no one ever catches you slipping in and out. [YouTube via Wimp]