things to watch for...
it might not be much of an issue with small powered lasers, but can be a problem as the lasers get bigger.
be careful where you're aiming the laser... even if it's properly aimed, sometimes it can get misaligned (weather, kids running up to it. etc...)
It might be enough of a distraction, it somehow it gets pointed into the street as a car goes by.
It might be an issue if someone decides to look into it. (people are curious, or even out looking for potential lawsuits)
If it points into the sky, and a pilot happens to see it, He's required to report it to FAA (which have been looking into an ever increasing number of incidents of lasers pointed at aircraft already.)
it sounds like a cool idea, but please be careful. even small lasers come with warnings.