Google has announced plans to expand further the number of services that it provides. Four new products have been introduced, Google Co-Op, Google Desktop 4, Google Trends, and Google Notebook.

Google Co-Op promises to improve the search experience for users, by syndicating their knowledge. It is now possible for users or companies to categorize Web pages, and make those pages available as a subscription. When people subscribe, these labels and associated links get added to search queries.

Google Desktop 4, will be enhanced to introduce Google Gadgets, which are small applications that abide on a user’s desktop or inside Google Desktop itself. I have no idea what these are like, but something similar to the widgets used by Konfabulator springs to mind.

Google Trends will allow users to access data regarding the popularity of search terms over time. It is possible to filter these results in certain ways. Google Notebook, on the other hand, is a scratchpad application that will let you store important URLs and other data copied from Web pages, and share that information with other users.