[Shendare]

It sounds like you would be better served with a Bluetooth proximity-based device like a Gatekeeper.

http://www.gkchain.com/gatekeeper.html

I haven't looked into the OTP functionality of it, since I decided to go with a YubiKey myself, but a friend loves it for hands-free automatic locking and unlocking of his computer as he comes and goes.

[escapologybb]

That looks great, thank you for the link. I would love to try one of those devices, I don't have great memories of this kind of unlocking though.

I can't remember the exact name of the product, but I installed it with good faith and it completely locked up my Mac so badly I had to reformat the computer.

So colour me a little reticent to try this, although if the gatekeeper guys are reading this I'll be happy to beta test one for you. You know, purely for accessibility reasons. :-)