Since this seems to be a thread for cool effects, let me share one that I learned from the early days of digital cinema. Pixelated video projectors can make an eerie 3-D effect by projecting images like faces bodies, etc. on a fountain of water. The smaller the drops and the greater the mist, the more impressive the effect.
Add Marty's lasers to the mix and you will probably feel stoned while maintaining clean urines!