5mW laser module - what would you do with it?
Besides keeping the cat busy of course. 
I have one recovered from a chinese flashlight where the batteries leaked. The flashlight used 3x AAAs but it appears that was just for the flashlight itself which uses white LEDs, as the module has a voltage drop of 2.27v at 24mA so it can be used with just two 1.5v cells, or one lithium ion. From 18mA up it hardly gets any brighter, so i didn't increase the current past 24mA - it seems this is a 5mW module.
I already thought of a cool use - a laser tripwire to trigger a prank on somebody. Since it is red and fairly bright, the receiver could either be an IR LED or just a regular transparent red LED. On a more professional note - modulating it to stream data at a distance, but that's been done already. I'm open to other ideas. And no it can't burn stuff unfortunately.
I have one recovered from a chinese flashlight where the batteries leaked. The flashlight used 3x AAAs but it appears that was just for the flashlight itself which uses white LEDs, as the module has a voltage drop of 2.27v at 24mA so it can be used with just two 1.5v cells, or one lithium ion. From 18mA up it hardly gets any brighter, so i didn't increase the current past 24mA - it seems this is a 5mW module.
I already thought of a cool use - a laser tripwire to trigger a prank on somebody. Since it is red and fairly bright, the receiver could either be an IR LED or just a regular transparent red LED. On a more professional note - modulating it to stream data at a distance, but that's been done already. I'm open to other ideas. And no it can't burn stuff unfortunately.