Most runners already know this but here's a reminder as spring race season gets under way.
Last year USA Track & Field, which is the sanctioning organization for our sport, banned use of personal music devices during sanctioned races. It's a safety issue - both for the person using the earphones and other runners. For example, I witnessed a runner who dropped her iPod just after the start of a race last year. She, of course, stopped abruptly to pick it up and several other runners had to scramble to keep from stumbling over her and crashing to the pavement.
It's also a safety/common courtesy issue when the earphone wearer cannot hear the approach of other runners or verbal instructions from course officials and volunteers.
For more on the ban, here's a New York Times article on AOLsports that was published late last year.
Run strong, live well & be happy!