If you have a laser pointer you’re not using, how would you like to turn it into a pseudo-spy gadget? With a few more parts from RadioShack, you can set up your own laser communication system to talk covertly just like these bowtie-wearing spy wannabes.
How it works: The audio signal from a microphone varies the power feeding the laser, so that its brightness changes, following the shape of the original sound wave. At the receving end, a solar cell or photo-resistor converts the oscillating light signal back into the original sound. Sound cool? Make your own with step-by-step instructions here.