Algodoo

Fairly standard point to point measurement algorithms here it can actually be done manually if you feel left out. Apart of some of my experimental (The "experimental" the the real time graphical calculations) scenes I've made which i never made presentable enough to upload (This scene was made sometime around late 2010).
I'll begin a dump of some of the others when i get around to it

Don't point laser directly at eye, i have no idea how the code will react to refracted beam