Google has updated its desktop search tool with an automated sidebar that learns your interests as you surf.

Google Desktop 2 is available for download here and gives users the ability to search their own PC and the web simultaneously. It also includes an intelligent sidebar that presents topics likely to be of interest and monitors RSS feeds.

Looking at the user's habits allows the software to filter the information in the sidebar feature, limiting the need for manual configuration.

The sidebar's 'web clips' delivers updates from websites that were recently visited based on the site's RSS feed, eliminating the need for the user to sign up. Another feature called 'Quick view' offers links to websites that are often visited.

"You can think of it as a personal web assistant that learns about your habits and interests to identify and present web pages, news stories, and photos that it thinks you will be interested in," said Marissa Mayer, director of product management for consumer products at Google.

Other improvements include a scratch pad to record notes, news and local weather reports. An Outlook toolbar has also been added to allow users to search their emails using Google technology.

The company is also keen to get developers involved and has published a set of application programming interfaces for the sidebar. One of the first to be published will add a 'To Do' list to the sidebar and others are available here.

The sidebar works in a similar way to the widgets that are offered through Yahoo's Konfabulator or Apple's Dashboard. Widgets are small applications written in JavaScript that present users with data from the web. 

Tom Sanders contributed to this report from California.