The act of overusing your camera from either taking a picture of the same thing multiple times, or taking a picture of everything you can find, or find you need to take a picture of. People who get a new camera often become snap happy.
Basically just using your camera a lot.
"Maria is so snap happy with her new camera she maxed out the 1 gig memory card in one day!"
That person that you work next to that is so happy you just want to snap their head off at 5AM
they are usually the person that asks you how your weekend was the second you walk into work at 3am at the local factory when you haven't even recovered fully from the weekends hangover yet.
"you know that new girl just makes me so Snap Happy when she acts so chipper in the morning."