Not-so ‘Special’ Effects
I saw the sci-fi thriller Surrogates last night. The story dealt with human-looking robots that would act as proxies in the real world. These "surrogates" (made in any image you choose) are controlled by their human operators hooked up to a computer and connected to a very expansive network. Think about The Sims or Second Life taken to the extreme. It was an interesting concept made dull by a standard thriller plot and little character development.
What I did find interesting was a sequence involving a military raid. When the soldiers were engaging in combat, they were not firing blanks, but digital muzzle flashes that were obviously added in post. Most probably wouldn't catch this, but I did. It was evidence that even Hollywood films need to resort to low budget techniques when necessary.
An effect like this is a simple composting trick, acheivable in most editors. Muzzle flashes can be found on the web (or created) and dropped onto your timeline. A flash of any kind will last one frame. Insert flash, adjust so it lines up with your gun for one frame (more if you want a machine gun effect) and you're done. Tweak to your liking. Don't forget the all-important sound effect!