By Frank Macek It's no secret DVRs have been changing the way Americans watch TV. The real news is how fast it's happening. People are increasingly watching TV on their own schedules, instead of the broadcasters. The good news is Americans are watching more TV than ever before. According to a new report by Nielsen, 30.6 percent of households in Nielsen's National People Meter Panel now have a DVR as of March 2009...that is up from 12.3 percent in January 2007. This can be contributed to the integration of DVRs into cable and satellite boxes. Standalone DVRs accounted for only 5% of this amount. Many households have more than 1 DVR...25% had two...5% had 3 or more in their homes. The report also found programs recorded between 8 p.m. and 9 p.m. were played back within the same day more often than those airing at 10 p.m. Therefore, DVR playback may have impacted live viewership of programs at 10 p.m. and later, including late news. The highest playback times during the week o...