Avoiding Check-Out Purgatory

In one scene of Indiana Jones and the Last Crusade, Indiana has to choose which cup is the Holy Grail.  His decision is literally life or death.  This is how it feels when choosing which line you will stand in at any large store. You need to take into account how many people are in each line, how many items are piled into each cart, the experience and efficiency of the cashier...plus the unknowns:  items missing their barcode, whether the customer's check/ATM card will work, and how long the customer is willing to argue with the cashier about the price of an item.  This doesn't even include the customer who wants to barter or the old lady with exact change (as if there's some kind of "exact change award").  All of these calculations, which could reduce a PhD physicist to tears, must be made in seconds...otherwise the opportunity is gone and a more aggressive shopper claims your space.
All of this could be avoided with a little common sense.  If one line is formed before all of the cash registers, then the next person in line is called by the next available cashier.  This ensures that, if one cashier gets stuck with a problem customer, everyone in the line doesn't suffer.  I've run across a scientist who sees things my way that can express this idea much more clearly.  If you click on the link, I'll take you right to it and you can see how he explains this concept:  http://www.youtube.com/watch?v=F5Ri_HhziI0
A couple of merchants have figured out this method of fairness for shoppers, but most still need to employ this type of Common Sense!