I was 2nd in line last year standing next to a walmart employee's wife. We stood next to each other as we went through the door.
About 30 minutes before opening people started showing up and just not even trying to get in line--just gathering as a crowd by the door. I kept talking louder and louder saying stuff like "boy...I'm glad I'm up here because of these rude line jumpers...."
On a side note, the guy got a phone call about 10 minutes before opening to tell me exactly where the laptops were. I sprinted straight to them, and the stack of about 20 was gone w/in about 30 seconds.