Google produced a new version of the Google Desktop tool, and added "personalised" search and bookmarking tools for users to refine their view of web content, and grade its relevance to them.

Desktop searching has been a hot area for the past several years, as people have found desktop search tools useful for indexing and retrieving information on their hard drives. Meanwhile, social bookmarking services such as Yahoo's Del.icio.us have become popular because they let users save links to Web sites they find useful, annotate the links and share them with others. Finally, vertical search is another emerging area, because it lets users look for Web pages about specific topics and thus obtain a narrower set of results.

In social bookmarking and vertical search, Google launched a test version of Co-op, a service that lets users put labels on Web pages about subjects on which they are experts. For example, a dentist could mark up Web pages about dentistry, and users could subscribe to his labels.

Already, Google has signed up users to annotate Web pages dealing with health and local events, but now that the service is open to anyone, users can label pages about any subject. The labels that users create will also help the Google search engine adapt its indexing and retrieval algorithms so it can deliver more relevant results.

Google also introduced a related social-bookmarking service called Notebook, a browser tool that lets users clip content from Web pages such as text, images and links and save them to a "notebook" which they can access from any computer and share with others. Unlike Co-op, Notebook is a single repository where a user can keep portions of Web sites he or she visits, along with notes. Google Notebook will be available next week at http://www.google.com/notebook.

On the desktop search front, Google released a new version of Google Desktop, whose main added feature is its ability to run mini-applications called Gadgets that extend the software's capabilities. They will run within the Sidebar feature of Google Desktop. Google already has hundreds of Gadgets available, and it is also offering an application programming interface (API) so developers can create their own mini applications. Google Desktop 4 Beta is available at http://desktop.google.com.

Finally, Google launched a service called Trends, which lets users see how popular a search term has been over time, along with relevant news items about that topic.

Jonathan Rosenberg, vice president of product management for Google, called Google Trends an opportunity for users to "create your own zeitgeist." He and other Google executives, including chief executive Eric Schmidt, spoke to journalists Wednesday on Google's campus in Mountain View, California, where the company announced the new services.

At first glance, the announcements may seem like a "willy-nilly" set, but they highlight the growing role that user-generated content and vertical search play in Google's products and search services, an analyst said.

"This is something they haven't focused tremendously on before, but they are now really tapping into these trends," said analyst Greg Sterling, from consulting firm Sterling Market Intelligence.

Google has been releasing services to users nearly as fast as the company can come up with them. It's all part of its overall plan to give Internet users access to as much information as possible, faster and more efficiently. But some have criticised the company for putting out too many products without fully articulating how they fit into its overall plan, as well as for the company's culture of being tight-lipped to press and analysts.

Elliot Schrage, vice president of global communications and public affairs for Google, promised on Wednesday that the company would be more transparent in its dealings with investors and journalists to alleviate confusion about Google's strategy.

Marissa Mayer, vice president of search products and user experience for Google, acknowledged that not all of Google's services are ready upon release, and that Wednesday's new services would be no different. She said Google prefers to release services, which are almost always free, as quickly as possible even if they are flawed.

"Because it's free, it shouldn't be perfect," Mayer said. "It's innovation, not instant perfection."

In a question-and-answer session following the services announcement, Google xo-founder and president Sergey Brin admitted that Google releases a few too many "beta" services that never achieve full product status.

"I think ... we've probably abused the word 'beta,'" Brin said. "I think what we need to do better is communicate the things we expect to work well. Really, you guys are the guinea pigs."