The humble asterisk is plaguing baseball fans these days. Do the records of Barry Bonds and Jason Giambi deserve to be singled out of illegal steroid use. There is doping in a lot of other sports. Like pigeon racing. Here's how it works. The birds are taken hundreds of miles from home and then released. The pigeon that flies back the fastest wins. So far so good. But some pigeon fanciers...as they're called...have been tempted to give their birds chemical assistance. Marketplace's Stephen Beard reports from the western England town of Cheltenham.