The good news: this Star Trek phaser mod has legitimate blow-em-up functionality and pew-pew sound. The best news: you can build one of your very own.
The full tutorial can be found at Laser Pointer Forums, a site I'll obviously be visiting with far more frequency in the future. In the meantime, I'm going to keep watching this video, imagining Romulan sentries in the place of big black balloons. [Laser Pointer Forums, thanks Jay!]