I purchased myself a 50mw green laser about 6 months ago (maybe more) and I have played with it every single day since I bought it.
It is the single most entertaining piece of technology I own haha.
I love taking it to Walmart and messing with people. Its one of my favorite past times lol.
Here is a cool "tunnel" effect me and my friend Htown rigged up one day. Sorry if there is some babbling in the background, we didn't know the camera had audio.
I actually just got a 100 mw blu-ray laser today...and I love the thing. I'll go shoot a video of that now, since I'm pretty bored and its a cool new toy for me.