pYro_65:
Grab a 50 - 100mw green laser off ebay, the beams are clearly visible, not just a dot. These lasers are usually way overrated ( mW ) and pwm can greatly reduce the actual output to a few mW, while leaving a nice beam. Got 2 off ebay for $9 each.
For pwm you will need a laser without a driver unless the driver has its own pwm input.
Diode lasers are not like LED's apart from the fact that they are an LED, They will instantly die from the slightest misuse, or at the least have their output dramatically reduced.Some general diode laser info, may be helpful
Thanks for the suggestion. The green laser would certainly up the cool factor. Of course, I only have a vague idea of what PWM means. I looked on ebay for 50 mW lasers and they were all $15-20 each! And the ones I saw, I think, didn't include a PWM input, but then again I'm not sure.