For you fellas that need to "mark" your location, check out the strobe flashers linked below. While these units are a bit heavy for hiking or EDC due to their single D-cell battery, the flashes they put out will definitely be seen. They are amazingly bright!! I've also seen these with a red lens to go over the xenon tube flasher assembly, as well as the usual clear lens. I keep one in my car so I can wear down a cheap D-cell battery that will not affect my car's ability to restart, unlike the car's built-in emergency tail light flashers.
http://www.emprep.com/Strobe%20Lights.html

BTW, thanks for the Pelican M6 review of performance in a real-world workout.