By the end of 2012, there will be an estimated 55 million tablet users in the United States, according to a study by eMarketer. Of those, 42 million (or 76 percent) will be using an iPad.

The perfect marriage of power and portability, tablets are quickly becoming the personal computing device of choice. But surprisingly, a Viacom study found that 74% of US tablet usage occurs at home, with 96% using it in the living room and 94% in the bedroom. It’s also a solo affair: Daily tablet users spend an average of 2.4 hours per day on their devices, 77% of which is time is spent alone.

Tablets aren’t all fun and games, however. Although 85% of tablet use is for pleasure, not business, three-quarters of respondents were at least somewhat likely to use their tablets in their home office.

Outside of the home, tablets were most often used in airports/airplanes, coffee shops and outdoor public spaces. Only 36% of respondents used their devices in stores, suggesting that tablets haven’t quite caught up to smartphones in the mobile shopping arena. But research has shown that tablet users are taking advantage of larger screen sizes to research products before they visit a store in-person.

Some other interesting findings:

• 62% use their tablets daily
• Most media activities on the tablet, such as playing games and watching TV shows, peak with the 18-24 demographic
• More than 50% of respondents said their tablet makes them feel happier and more relaxed
• 49% said tablets make them more effective at managing life
• 39% said tablets boost creativity
• 40% agree that “my tablet brings out the best in me”

With video capabilities, endless instant information and social experiences galore, the tablet truly is a jack-of-all-trades. Marketers need to give serious consideration to how their strategies render on a tablet. Have you fine-tuned your efforts to meet the needs of this incredibly diverse (and rapidly growing) market?