SHTF/Camping Perimeter security?

[00tec]

You could probably build something neat with an IR laser diode, a few mirrors, an IR sensitive photocell and a few other components. Power it from the house or car battery so you don't have to deal with small cells. Setup would be a pain unless you had night vision or a digital camera to see the IR beam.

[brianut]

$18 wireless driveway alert system.
Ideally they would have different frequency to know where the breach was, maybe you can change the tone or something.

Just the basic idea

http://www.harborfreight.com/wireles...tem-93068.html