At least for the PS2 launch in SF, CA, At the Metreon's Sony store. Sony gave out numbers and there were "line holders" if you needed to go to the bathroom. They even gave out food and free-stuff, specially for that dude who was first in line.
10) Folding Chair 9) Rolling Ice Chest 8) Blanket 7) portable tv /radio/something 6) FOOD 5) replacement for breaks :girlfriend/boyfriend(friends) 4) body guards, 3) heavy duty clothes if there is a stampede 2) knife 1) police protection