This is such a no-brainer it's hard to figure out why it hasn't happened. Certainly it is harder to reverse engineer than to build from scratch. And yes, I'd want a manual backup in casre there was a power outage. But that's not enough of a reason not to proceed.

http://www.findarticles.com/cf_dls/m3092/7_39/61641064/p1/article.jhtml

There are several of these products on the market, including for inside and outside doors, garage doors, gates, etc. Some work off batteries that can last up to 5 years (according to one manufacturer), and quite a few can be linked to alarm and access management systems. In some cases you can even type in the access code from your cell phone so that your gate opens as you come driving down the road.

Great idea! My co-worker already made this though. He has a "key card" in his wallet. When he get's within 5 feet of the door, it not only unlocks but also opens. He installed it 2 years ago and it works great. He also has his garage door opener built into his headlight, flashes the brights and the door opens.

I first heard of this being available about 6 months ago. As the hyperlink above shows it is now produced by at least 3 major manufactureres and can be purchased at any major hardware store. Good idea though - and glad it is here.

This is another case of the effect of technoloy in our lives. We want everything to be as convinient as possible..to be easily accessed. Yes, I believe that some people are already doing this and it will be a trend in years time to just have everything in a card..probably everything that you need to open in the possession of a single card! how convinient..

I took this one step further in the "Security" area of this sitewith a proposal to combine an auto and house keyless entry. Withthe sophistication of digital encoding, I can imagine a singlekeyless remote capable of unlocking all your doors with a greater degreeof security than hard keys - and, think of the convenience