Steve Hoefer’s secret knock detector is little more than a piezo speaker, a tiny gear reduction motor, an Arduino and some PVC pipe — basically a bunch of stuff he had lying around the lab. It works by keeping track of the time between a pattern of successive knocks. It’s probably not the most secure way to lock a door, but Hoefer notes that there is a lot of room for improvement on this design. Besides making it small enough to actually fit in a doorknob, you could program it to accept a variety of knock patterns, including different knocks at different times of the day. Hit the link for instructions on how to build one yourself. [Grathio via Make]

The locks allow remote status checks and changes, so anywhere you’ve got a secure internet connection, you can lock and unlock the door at will. It’s also got a ton of extra features, like turning on customised lighting when you enter the door or notifying you via email of anyone going in and out of your house. This is all done by Kwikset’s marginally paranoid Connect4 system, and it’s likely to cost a pretty penny. But I’d definitely pay a premium to be able to know for sure whether I locked the door. [Kwikset via Engadget]

The folks at Wired have taken a peek into the life of one Marc Weber Tobias—a man that obsessively pits himself against the toughest physical security systems that modern technology can muster. Unfortunately for manufacturers, Tobias hasn’t found a lock that he can’t pick, crack, or bump.

As you can see in the video, Tobias and another security expert by the name of Tobias Bluzmanis were able to take out several high-security Medeco3 locks without so much as breaking a sweat. Impressive for sure, but the real problem is that Tobias makes the how-to of his lock-breaking public—all under the pretense that his work “makes shit better.” That may be true, but there is no doubt that he takes a joy in the work that is…well damn near criminal. Check out Wired for the full story. [Wired]

If you’re tired of carrying a lock around with you every where you ride, the Freelock is a self-locking bicycle whose seat also functions as a built in lock, which is apparently as secure as an old bicycle with a typical chain lock.

The handlebars and body of the bike can rotate around to accommodate different angles of the poles and racks the lock latches onto. Sounds like it would be a quite handy concept, but I’m sure the idea of lugging around a chain lock won’t be so bad once you realise your tires have gone missing… again. [Yanko]

Here’s how it works: In the initial setup, you program a time limit—say, 20 minutes—for your future bathroom. From that point on, whenever you close the door and activate the alarm, the Help Lock will sound a preliminary alarm after the allotted time, giving the bathroom inhabitant 30 seconds to deactivate it. After that, the doorknob will initiate an alert call to whatever number you’ve chosen to enter, whether it be a neighbour or emergency services.

The concept seems like a pragmatic approach to a real problem for senior citizens, but begs for one minor modification. Does forcing an old person to scramble from a bathtub to deactivate an alarm that your forgot about sound like a good idea? Throw another minute on there and we’ve probably got a winner. Check out a more in-depth description of the Help Lock’s functionality at [Yanko]

Designed to work with most HDMI components and most HDMI cords, the premise is pretty simple. The lock uses either a screw or adhesive to stick itself around the HDMI port, forming a sort of outer port that can clamp to your HDMI cord. At $US20 a pair, the EZ locks cost as much as some HDMI cords. But then again, if you’re spending thousands or tens of thousands on your home theatre setup, maybe they’re not a horrible investment. [Blue Echo via Engadget HD]

Keyhole Surgery is Operation reinvented for lockpick enthusiasts. You view a 3D schematic of the lock on the computer, then try to guide the key through the maze of tumblers without striking the walls. He who has the least mistakes wins. He who has the most mistakes will require a good lawyer.

A concept for now, if you really like the device, we’re sure some perceptive, agile manufacturer will come around to borrow the idea soon enough. [Moritz Waldemeyer via bbGadgets]

* Not a real story at all – I made it all up. I haven’t owned a bike in years…

[Mike Lambourn via GizMag]

Apparently, the problem with that was that the knob had too much surface area for the sensor—but I don’t see why the entire doorknob needs to be utilised. It would be even more secure if only touching a specific section would grant access. If you want to try it yourself, the complete instructions are available on the project page. [Washington.edu via Hack-a-Day]