Nearly 20 percent of American households are tuning into TV over the Internet. That's twice the number from 2006, according to new research from The Conference Board Consumer Research Center and market-research firm TNS. The most popular destinations for online broadcasts? The official TV channel home page and YouTube.com.

The growing movement toward watching TV online is attributable, in part, to schedule-bucking viewers who want to watch the shows they want to watch when they want to watch them. Other reasons for the rise in online TV viewing include portability and the ability to skip commercials.

Specifically, 43 percent of online TV viewers tune into the news, 39 percent watch drama shows, 34 percent view sitcom/comedy shows, 23 percent watch reality shows, 16 percent view sports, and 15 percent view user-generated content. Previews, additional content from favorite shows, soap operas and advertisements are also gaining the attention of online TV viewers.