I must say, I enjoyed reading this thread, it was very entertaining
Actually a long time ago (high school) I played around with an idea of a light bomb. The main principle being that light itself can used for energy storage.
In theory, with a lot of materials and some tech that just doesn't exist yet, it's interesting.
Biggest obstacle is the speed of light though, but imagine if it were possible to create a closed system with a near perfect vacuum and near perfect reflective surfaces... would be very interesting battery - a sphere of pure light.
Depending on the quality of the mirrors and the vacuum, this would be a bear perfect battery... or weapon.
Of course I realize there are many holes in my little daydream.
Coming back to this thread though... a flashbang grenade does the job just fine.