The document discusses 4 hot trends in mobile: 1. Social TV - using tablets and smartphones while watching TV and social apps like GetGlue and YapTV. 2. Group texting - messaging apps like GroupMe and BelugaPods that allow group conversations. 3. Photo sharing - more specialized photo apps that focus on daily photos, filters, or location-based sharing like Instagram. 4. Scanning - apps that bridge the physical world to the online world instantly by scanning codes and items like with Google Goggles and Shazam.