Occupancy detection ?

["Marcus Warrington" <marcusw@xxxxxxxxxxx>]

Having played with some X10 kit and misterhouse,I'm eager to get the whole
house setup to turn lights on as we go from room to room (and more
importantly turn them off when we leave). I was originally going to use
some X10 Hawkeye units but having played with one I find that they don't
really work too well for occupancy detection. The biggest problem being the
10second blindness after a transmission, meaning that if it turns off (no
movement detected) while you are in the room you sit their waving your arms
for 11 seconds before it turns the light back on. There's also the issue of
speed, it takes around 1-1.5 seconds to turn the light on (using
misterhouse + Hawkeye), at least 50% of this must be down to the RF + the
X10 transmission to misterhouse. What I would like to do is hardwire some
PIR's back to the PC so that the only delay is the transmission from
misterhouse to X10 light. I'm sure this has been done.. but what PIR's did
people use (I'm thinking of 360degree ceiling ones) and what did they use
to
interface to the PC ? I need about 20 PIR Zones to cover all the rooms.

Maybe comfort is a better (expensive) way to go ?

I assume cat5e should be more than adequate for connecting the PIRs

Marcus