Outrageous Patent granted to IBM

Slashdot reports that IBM was granted a US patent for cash register software that remembers "paper or plastic" for each customer, relieving the clerk of the onerous task of asking. This trivial and obvious idea is worthy of patent protection? Can you say "patent troll"? Can you say "welfare for patent lawyers"? Can you say "Patent examiner with the IQ of an Ipswich clam"?