Crimson Trace Green Laser rides atop my 14" barreled Mossberg Shockwave 12 gauge.
I probably shouldn't try lighting up road signs with it though.
I've been thinking about replacing some overhead 4' fluorescent hummers with white LED's. After reading on this thread about them being harsh on one's eyes I'm having second thoughts. Might just toss the noisy fixtures and go with "soft yellow" fluorescent.
I haven't shot mine yet. Academy ran a sale on them a few months ago and it followed me home.