While mobile phone users have thus far shown little interest in watching TV programming on them, NBC may have identified a large niche audience that could find such programming appealing: gamblers. NBC announced Thursday that it plans to make its coverage of the Preakness Stakes horse race available live via Verizon's V-Cast Mobile TV service. While gambling was not mentioned in its release, it appeared obvious that there could be wide interest in checking out the race results among those who place legal -- and illegal -- bets on the outcome. The mobile telecast will be available in 30 markets, including New York, Chicago, Philadelphia, Las Vegas and Atlanta, at 5:00 p.m. Eastern Time.