I had a similar experience to tekchic at Best Buy. It was my first Apple launch day line experience ever. (I always preorder online.) I got there about 3:30 and was about 15th in line. The first guy in line got there at 7:00 and set up his own numbering system; as people walked in, he would give them a scrap of paper with a number on it, just to keep things civil until the 'official' line began right after I got there. 15 minutes after I got there, the line went crazy. It wrapped 1/3 of the way around the perimeter of the store, and it's a fairly large Best Buy. At 4:30, they went around the line handing out the sheets with the model you want, representing the entire stock. Then at 5:15, they finally started selling them. They probably had about 150 in stock on a cart. Very limited accessories; about half of the Smart Cover colors, one bulky leathery case, and the Zagg front-only screen protector, but a decent quantity of each item.
The only thing I didn't like was that they had people from different departments walking down the line trying to sell us other crap. The guy from BB Wireless was trying to sell us MiFis and LaptopConnect cards, because an AT&T mifi is "faster than an AT&T iPad". Fortunately a guy in line proved him wrong with SpeedTest.net on the spot, and brought up the fact that it's twice the price/mo. 😛. Another guy walked around trying to sell us BB protection plans, and trying to sell us on the idea of BB buyback.