A new manufacturing process could cut the cost of making crystalline silicon wafers for solar cells by 80 percent. The process is being developed by Lexington, MA-based 1366 Technologies, which this week showed off the first solar cells made this way.

Thanks to smart phones and other mobile devices, the number of applications that make use of geolocation data is exploding. But developers and device makers face new challenges that include determining physical location accurately, turning coordinates into meaningful information, and protecting users' privacy.Last week, Twitter announced that it would supply developers with richer geolocation data. For users who activate the feature, Twitter already provides the latitude and longitude information through its application programming interface (API). The new data will add meaning to those coordinates: the relevant country and city, as well as the identity of a neighborhood or nearby landmarks and businesses. This is a direct result of Twitter's acquisition of geolocation startup GeoAPI in December 2009.

Recent research shows that the typical PC user needs to install a security update roughly every five days in order to safely use Microsoft Windows and all of the third-party programs that typically run on top of it. In response, a Danish computer security firm says it will soon debut a free new service that silently automates the installation of security updates for dozens of the most commonly used software products.

In the wake of a massive public-relations nightmare involving brake problems in its cars, Toyota is investigating two more reports this week of unintended acceleration in its vehicles. Both cases involved Priuses: one in Harrison, NY, that resulted in a crash, and the other on an interstate east of San Diego. The troubled carmaker has already recalled 5.4 million cars.