At 2011 Defcon, it was literally a case of “oooh, shiny, me waaaant!” Several of my geek friends, including Meredith, had nifty blue and violet lasers that seemed much brighter than usual. Especially in smoky casinos, they left trails that rivaled any Star Wars blaster trails.
Turned out that these were all lasers built from Survival Laser parts bundles. FDA-regulated lasers top out at 5mW, while these range from 300mW to about 2W in a variety of colors. The other interesting feature was the adjustable lens, so the laser could be focused into a tight dot a mile away or a 12ft “flashlight” circle at a hundred meters.
I ended up with the basic red kit because it had no limits on runtime. Some of the more powerful lasers overheat after a few minutes and have to be cooled. My original plan was to use it in a slightly de-focused form on a shotgun, but I am still unsure about the recoil resistance of it nor have I been able to improvise an adjustable mount. In the meantime, I’ve used it to point out features on a landscape to friends. These lasers are much more powerful than the typical consumer model, so they actually have visible trails provided even a little moisture or dust int he air. They also seem to run a very long time on a single rechargeable battery, so they might be useful for signaling. More scientifically minded folks might find more uses for it.