I recently installed a holographic heads up display projection sight on my AR-15. Which not only greatly improved my 100 yard kill zone percentage, but moving target acquisition is also faster and easier.

I bought an EOTech 552 Sight, which has a night vision dimming function, 20 intensity settings, auto 4hr (or 8hr) shut-off, and is submersible. I have been utterly pleased with how accurate it has made my shooting. With a bipod, I can get 1" grouping at 50 yards!
Just for curiosity I went to the EOTech website and discovered that L-3 Communications has bought EOTech, which is just great, L-3 is already very involved with providing military technology to our armed forces, and this merger is bound to improve EOTech product offerings.
But here is the really good part, they have a simulator on the website for the Holographic Weapon System! http://www.eotech-inc.com/index2.php
Just below the main ad photo, 2nd box from the left.