Lockitron lets you unlock any door with your phone

Keys, wallet, phone -- the pocket-patting mantra as you leave the house is about to get simpler, thanks to Lockitron. Lockitron is a new gadget that lets you lock and unlock any door with your phone, from anywhere in the world.

Lockitron is produced by Apigy, an American start-up company founded by university friends Paul Gerhardt and Cameron Robertson. Gerhard told Mashable that "the idea is to replace keys entirely, everywhere from your home to your car to your gym locker".

When you sign up, you'll receive a Lockitron deadbolt kit containing the Wi-Fi-controlled deadbolt and a base station with a USB remote control. Install the deadbolt on your door and configure it on your phone, and you're ready to start locking and unlocking with your mobile.

Then, wherever you are, simply select the door you want to access and tap the lock or unlock icon -- hey presto, the door will unlock. You could be a thousand miles away and still let in a visitor, plumber or forgetful housemate. If there's no Wi-Fi connection, you can unlock the door and grant other people control of the door via a text message.

The kit costs £300 (£185). Here's a video of Lockitron in action:

Any smart phone can use the service over the Web. Apps are in the pipeline for the iPhone and Android. The Lockitron system will even work by simply waving an NFC-enabled phone at the lock. NFC (near-field communication) tech is becoming increasingly popular, allowing phones to pay for things and enabling you to play Angry Birds with other phone users.

The big concern is security. The online service uses the secure HTTPS protocol, and Lockitron promises data is encrypted and protected by firewalls. Doors are opened by the same pulses used in wireless key fobs. You could lose your phone of course, but then you could lose your keys.

Lockitron is one of the coolest examples we've seen of the 'Internet of Things' -- the idea that real-world stuff can be connected to you and to other stuff via the Web. Google recently announced its own take with Android @ Home, which turns your Android phone or tablet into a remote control for everything electrical.