I haven't built my own laser yet. (I'm pretty new here.) However, remember when there were only little red laser pointers at the store and they were something like $10? Then, suddenly, there was talk about there being green lasers? (I'm refering to my own experience as this was all way before I knew anything at all about lasers and still don't know much...) I was like, oh my freaking god, I have to check this out. So, I bought a <5mw 2AAA greenie from Radio Shack (I forget the nm.) for about $50.
I bought it thinking (with my ignorance) that it was the holy grail of hand held lasers (because I never really looked around anywhere except the local electronics stores of which none had any powerful lasers.)
So, I buy this thing and play with it for a few days. Then, I come across this youtube video where this kid shows you how to drill a hole in the back side of it and turn this knob/screw head thing inside to make it burn stuff. I remember thinking: "Where's my drill!" Next thing I knew, I turned the knob and poof! No more green laser beam.
If only I knew about LPF back then:
http://laserpointerforums.com/f51/pot-modding-faq-s-40510.html
But, if it wasn't for that rediculous thing I did to that horribly overpriced pointer, I never would have gotten back online and researched what I did wrong. Those searches are what eventually led me to discover that there are way more powerful (and more colorful) lasers out there. Not only that, but now I've joined this online community of people who actually like lasers even more than I do. (I never would've guessed that a site like this existed.) Now, the more threads I read, the more my interest grows and I'm sure, one day soon, I'll end up converting one of my spare rooms into a laser friendly work zone.
Stay tuned! More tragedies to come!