Over half of all US mobile phone owners use their phones while watching TV

"Half of all adult cell phone owners now incorporate their mobile devices into their television watching experiences. These “connected viewers” used their cell phones for a wide range of activities during the 30 days preceding our April 2012 survey:
38% of cell owners used their phone to keep themselves occupied during commercials or breaks in something they were watching
23% used their phone to exchange text messages with someone else who was watching the same program in a different location
22% used their phone to check whether something they heard on television was true
20% used their phone to visit a website that was mentioned on television
11% used their phone to see what other people were saying online about a program they were watching, and 11% posted their own comments online about a program they were watching using their mobile phone
6% used their phone to vote for a reality show contestant
Taken together, 52% of all cell owners are “connected viewers”—meaning they use their phones while watching television for at least one of these reasons."
Source:  Data from Pew Internet & American Life Project, 17th July 2012