A new study has revealed that nearly 20% of US smartphone users are utilizing check-in services like Foursquare. 16.7 million people, or 7.1% of the mobile audience, have leveraged this type of platform in March 2011, with 12.7 million shoppers recording their current whereabouts through a smartphone.

These users were roughly split between the different platforms, with 36% using a Google Android powered device, 33% using an iPhone, and 22% via a RIM BlackBerry. Those in the 25 to 34 year old age group accounted for the percentage of check-ins at 32.5%, while those in the 18-24 age group were close behind with 25%, and 35 to 44 year olds accounted for 18%. The active community utilizing check-ins was mainly comprised of those employed full time at 46%, and full-time students accounting for another 23%.

Nokia has filed another legal complaint against Apple with the U.S International Trade Commission (ITC) for alleged violation of of its wireless patents. This latest filing now brings to 46 the number of patents that Nokia has in suit against Apple, and many of these were filed before Apple even made its first mobile smartphones.

Nokia argues that Apple has been building its products using Nokia's proprietary innovations for years. This most recent ITC complaint centers on seven patents related to multitasking, data synchronization, positioning, use of Bluetooth and call quality. Given that Nokia has recently partnered with Microsoft to make the MS smartphone software platform Windows Phone 7, they may have added incentive to make Apple's life difficult. Together Nokia and Microsoft will seek to challenge the iPhone and the Google Android smartphones that currently dominate the market.

Some manufacturers are blaming netbook computers for reduced sales and profits, but analysts say that weak sales could be a harbinger of broader weakness in the PC market. Netbooks were once billed as the rising stars of the computing world, but that was before tablet computers entered the scene.

Some companies are claiming that their core laptop and desktop PC business remains strong, and that netbook sales are still growing but at a slower pace than expected. Critics argue that this view of the PC market is too optimistic, and they are skeptical that netbooks are the only thing holding back sales. They point to research which shows that PC growth overall has been weaker than expected this year, and if this trend continues they expect more companies to lower their guidance going forward.

With some declines in the PC market overall, many retailers are selling their netbook computers and other laptop devices for cheaper, resulting in better buying opportunities for consumers who want a portable computer device.