Google has launched the first beta of Google Desktop Search 2.0, its desktop searching tool.

The differences between the two versions are significant and we are not dealing with updated functions and an improved interface, but with a change in concept. The central element is now a set of panels, called Sidebar, which can be moved in the left side or the right side of the screen. Up until now, Google Desktop Search has been accessible only through the Deskbar.

The Sidebar features a series of mini-applications, similar to the widgets, whose purpose is to display news: RSS or Atom feeds, images, stock market information or weather information.

One of the most interesting features of Google Desktop Search 2.0 is that it can decide which information will be displayed in the Sidebar; this is done by analyzing the user's activity. For example, for the news, Google will analyze the most accessed sites and will display news from those sites through the Web Clips panel, which will automatically index the RSS.

Google Desktop 2.0 is also able to monitor the e-mails received in the Gmail inbox and it also includes an Outlook Search Toolbar for the messages received via Outlook. Those who are afraid that by giving Google access to information on how they spend their online time they are jeopardizing their privacy, can also choose to encrypt the index. In this case, the searching process will be slower.

Another extremely useful panel is Quick View, which memorizes the last accessed programs and sites. With Quick Find, the searched files will show up immediately after the first letters are typed in, a feature which is very similar to Mac OS X's Spotlight.

Since Google gives programmers access to Google Desktop Search's API, there is already a series of freeware panels, which can be used for other functions.