Scott Lock's post about people wanting to enter 1-800-CALL-ATT into a phone field reminded me of a data entry "problem" some students of mine ran into a couple years ago. Keep in mind that while I live in the wonderful city of Louisville (15th largest US city), it happens to be surrounded by Kentucky. Anyways, these students from eastern Kentucky (think the Hatfields' home) happened to be doing some type of batch updates. If I recall correctly, they were trying to get a whole bunch of records from one hospital merged into another system. Problem was, in this batch of seemingly properly formated data, it was failing to do the update. So they went to task finding the problem record.
This issue at hand: Someone's first name was "#1 UK Fan" and the checks on the system didn't like # in people's names.
My dad had a friend in college whose last name was List. The system his college used would print everything in memory (or something like that) if it encountered the keyword list. He went through school with a last name of List*. Although looking at how some of the high school kids are spelling their names, I wouldn't be surprised if someone manages to accidently produce a sql injection query into their lastname. Scott; 1=1'// or something like that.