My 3 has also worked perfectly, though I don't carry it with my keys much. When I do, I keep it in "auto-off" mode so the batteries won't drain easily. I have a 2, but don't have much faith in it- that open switch is such an obvious entry point for water/moisture/dirt.<br><br>I'm amazed I haven't heard about this S.O.S. flash mode- I was one of those who sent them e-mail asking for it, and it was once a subject of conversation here. IMHO, this is a fairly important development, it puts the Photon far ahead of the competition for consideration in a PSK, and I'll buy at least a couple right away, especially for my "sailing" kits. I'm reluctant to order from REI, though, as the website makes no mention of this feature, and I'd want to be certain of getting the latest version. The local REI still doesn't seem to have the Photon 3 at all, just the 2.<br><br>I just checked the Photon site, and it doesn't seem to mention the feature either.