Take a look at this, it’s called TEO and it’s a padlock which uses your phone’s Bluetooth capabilities to activate the locking mechanism and unlock the lock!
The Bluetooth powered locking system is currently seeking funding on Kickstarter and has a rather useful feature, Bluetooth access, this means not only will it be fairly easy to use, i.e. using your phone, but you will also be able to send virtual keys to other people, such that you could share a lock with other people and not risk loosing keys.
The TEO is an excellent idea for use in clubs with various people all needing to access a room of equipment at different times, or something as simple as you forgetting to get something out of your college locker and sending a friend a key so they can get it for you.
The system has its own Bluetooth chipset built-in so security should be good; some people have expressed worry at the fact that it requires power, however the developers have stated that it should work for a year without needing to be recharged, and that they are working on an opening method for use if either your phone or the lock runs out of power.
If you want to know more about TEO you can head to their Kickstarter page where they’re currently looking for CAD$165,000 to fund the project.