It’s a bit like the Millennium bug that threatened applications that were not prepared for the year 2000.  Some older dial gas pumps were not designed to exceed $3.99 per gallon and did not have “4” as a possible dollar amount.  Now that gas prices have shot past the $4 mark in many places; smaller, older service stations are in trouble.  Many mom and pop shops cannot afford the tens of thousands it can cost to replace the pumps.  Furthermore, it is illegal to sell gas from a pump that cannot register the price correctly.  That said, regulators understand the bind that small service stations are in and have allowed them to stay open so long as they can demonstrate they are working to retrofit or replace the pumps.  In the mean time, service stations must calculate the price of gas manually.  I suggest we keep gas below $4 a gallon to help these guys out, what do you say?  More detail can be found in this Article from the Seattle Times.