Whether you're a regular presentation giver or you just like to pop balloons and start fires, laser pointers have become much more common, albeit unsafe, household objects. Here's how to build a small rig to test your laser pointer's safety.
A recent study by the National Institute of Standards and Technology found that some cheap laser pointers are especially notorious for emitting too much infrared light, meaning they're much more likely to cause vision problems if you aren't extra careful. Luckily, if you've got a digital camera, a webcam, a CD, and some paper cups, you can test to see if yours is one of the worse offenders.
Apart from being a good safety test, it's actually a cool little project—since webcams often are often more sensitive to infrared light, you can compare a direct photo of the laser beam from a webcam and a similar picture from a normal digital camera to see if your laser pointer has a higher infrared output than it should. Hit the link for the full instructions.