I found a great site that has a list of them and how to find them.
SO go back and rewatch some fo your movies and get more out of them!
I've found some on my own just by moving the curser around using y remote. Things get highlighted and I push enter. Sometimes cool, sometimes lame. Kevin Smith has one on Mallrats that brings up a clip of him telling you to stop looking for eatereggs and go do something useful with your time.
I needed a good way to kill more time.....