WRAL-TV Raleigh, North Carolina (a Capital Broadcasting Company) likes to be first when it comes to new broadcast technology testing and deployment.

The first U.S station awarded an experimental HD license by the FCC, (June 1996)

Claimed to have produced the first live sports program in HD (on September 6, 1997)

First HD newscast (on October 28, 1998) stats via Wikipedia

July, 2008 WRAL has just concluded trials of MPH or Mobile-Pedestrian-Handheld mobile video technology, developed by Harris Corporation in concert with LG Electronics.

Jimmy Goodmon, CBC New Media Group Director of Technology gave us more granularity about their dierction for MPH.
   

IpTVe
How long do you anticipate the trials to last and do you have a soft launch date for going live?
 
Jimmy Goodmon
We completed the trials last week and were impressed with the results. In terms of a soft launch date the answer is nothing is set in stone right now. There are way too many variables in place for us to make an estimate on a launch date (be it soft or not). One of those variables playing a role in terms of when we go live with mobile TV is the availability of receivers. Since mobile TV enabled devices are projected to be in stores sometime in 2009 we will have to wait until that time to better gauge the market.
 

Full Story: WRAL-TV, leading broadcasters towards MPH™ (Mobile-Pedestrian-Handheld)