Automatic screen lock when leaving desk

[Frederique Rijsdijk]

Hi,

I'm looking for a way to automaticaly lock my X session when I leave my
desk. Probably just using 'xlockmore -mode blank' or such. But how to
detect?

It could be infrared based (heat signature), video based (webcam w/
motion detection) or even mechanical (switch in seat? meh..).

And how would FreeBSD interface with such device? Most likely via USB,
since my lt doesn't have any serial ports.

Any ideas? Experience?


-- Frederique