Unlock doors with a remote or a cell phone

In the car industry this little gadget is old news: a remote control key. But somehow most people are still struggling with their shopping bags in one hand and about 20 keys in the other if they want to open the front door. LOCCA is selling a do-it-yourself kit so you can make any door swing open with the push of a button. It has a range of 50 meters and can store up to 19 keys. Obviously you'll have to install special receivers on you doors but LOCCA claims the installation is a breeze.

If those 50 meters aren't good enough for you, you can always build a device to unlock doors with a phone call.  That might come in handy if your guests are at the door and you're late. So: "I'll be there in an hour but I'll unlock the door for you. Make yourself comfortable", might save some people some friends. Unfortunately you'll need some technical knowledge and a spare prepaid phone to complete this DIY guide.