[rms]

It's being rolled out slowly. Target in Emeryville has a rather advanced queuing system like this, but customers definitely don't like it and don't necessarily realize it's faster, perhaps because Target has less cashiers as a result of the decreased wait.

Edit: Yelp says this line system has been eliminated. http://www.yelp.com/biz/target-emeryville-2

[xsmasher]

I went through that system a few times. They had a set of three lines (A,B,C) that fed a bank of cashiers; a screen overhead flashed instructions like "A => cashier 7", then "B => cashier 5" and then "C => cashier 1".

It felt more stressful, efficiency be damned. You spend more time at the "front" of your line (A,B,C) , waiting for the board to change. In a traditional system you can hook in behind someone and "zone out" / chat with your SO until you reach the register. In this system I felt like I had to pay attention the whole time and I was interrupted every time the bell rang, even if it was A's turn and I was in line C.

[rms]

Yes, you're right. The first time I did it I actually did zone out and had basically no idea what was going on. I think I missed my turn and eventually accidentally brazenly walked up to a cashier that probably wasn't assigned to me. The second time I did it I was more appropriately stressed and obedient.