Build Advice Proximity Sensor

I want to rig up a circuit or kit of some kind that will detect when I am nearby.

I want it to unlock a latch when I am within around a metre of it.
I don't mind carrying a keyring type thing or RFID tag to make it work.

I have no idea of what sort of thing to start reading up on to figure out where to start.

Any ideas on where to look to get started?

 

Hey,what do you mean by unlock a latch?? what do you want to happen when you walk by... something to open?

 

At mains power? Something like this?

http://uk.rs-online.com/web/p/lighting-controllers/7009281/

 

As ever, the devil is in the detail!

Probably need to be battery powered as there arent any plus nearby.

I want a door to unlock when only certain people get in range.

 

I use Home Easy stuff for my lazy man's non-techy home automation:
http://halx.co.uk/home-easy-remote-control-door-release-lock-en.html
http://halx.co.uk/home-easy-he851-remote-control-indoor-pir-unit.html
Possibly cheaper or less out of stock elsewhere.

EDIT: Ah, you mean when you personally are nearby. That might be an issue with the above

 

Thanks wolfticket but as you noticed it needs to identify me or a tag of some kind.

 

do you mean something like this

 

That's the sort of thing.
Now just need to find a way to do similar for 1/4 of the cost!

 

there is an nfc shield for arduino is this any good