Google will extend its search, social-bookmarking and desktop-search capabilities with new and improved products.

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

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

Google has already signed up users to annotate 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.

Next week Google will introduce a related social-bookmarking service called Notebook, a tool that lets users clip content from websites 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 sites he or she visits, along with notes.

Google has also released a new version of Google Desktop. This version can run mini-applications called Gadgets that extend the software's capabilities.

Finally, Google has launched a new 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, senior 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 CEO Eric Schmidt, spoke to journalists Wednesday on Google's California campus, where the company announced the new services.

Google has been releasing services to users nearly as fast as the company can come up with them. It's all part of its plan to give internet users access to as much information as possible, faster and more efficiently.

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 co-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."