SOUTH BEND — If you ever wondered how much difference just one letter can make when it comes to a message, ask the thousands of people who drove by a digital billboard near the intersection of Ironwood and State Road 23 between Thursday and Monday morning. The ad urged people to go to the "southbendon.com" website for a look at the "15 best things about our pubic schools." That's right, the billboard said "pubic" instead of "public" schools. The letter "L" had been left out of the word public. Lee MacMillan of South Bend said his wife spotted the error...