[vrindner]

This is obviously off-topic but,

does anyone know much about Radio Frequency ID systems used for keyless entry?

The current Mercedes SL-500 has it so that the door automatically opens when the owner is close to the car (assuming the owner has the RFID token on his keys in his pocket).

Toyota also offers it in Japan on their Toyota Prius.

Does such a system exist for residential use?

 

[Brian Puccio]

Yes, many offices make use of them, talk to any local security company. I don't know anything of installing it yourself, though I'm sure you could if you knew where to get the stuff. Sorry, I don't know any more.

 

[vrindner]

Wow, that was a fast response!

I'll try that route.