Penguin Radio - UK racing radio shows broadcast online
Race Day Las Vegas - with Ralph Siraco, 9-10am weekdays and 8-9am weekends Vegas time.
Racing Victoria Video Replays - from Australia, includes the full Melbourne Cup card, Cox Plate, and Caulfield Plate plus the daily race. Pay service now but some free samples.
The Roger Stein Show - live Saturday and Sunday from 8-9am Pacific time on KLAC 570/am
Sports On Air - lots of online video and audio for UK horse racing