Yahoo today announced the beta launch of its long-anticipated Yahoo Buzz, a Web extension where users can vote on what news stories or videos they think are the most interesting.

In addition to the Buzz site, which closely resembles Digg in its format of ordering the most popular stories on the Web, Yahoo will also place the top-ranked content on its home page.

Yahoo Buzz comes as the company's latest effort to transform itself into the indispensable starting point on the Web by opening its platform to the people and bringing in more relevant content to its home page.

"Yahoo Buzz is a good example of how we are continuing to innovate and open up our key starting points to third-party publishers, making Yahoo more social and personally relevant for our half a billion consumers," Jeff Wiener, executive vice president of Yahoo's network division said in a statement.

In that spirit, Yahoo will also be opening the interfaces of its search and e-mail applications, giving users APIs that will allow them to annotate search results and create a smarter inbox that can group and prioritize messages by looking at a user's circles of connections across various social sites.

CEO Jerry Yang announced the changes coming to the inbox at the Consumer Electronics Show last month. The search announcement came today at the Search Marketing Expo in Santa Clara, Calif. Amit Kumar, Yahoo's director of product management, detailed the forthcoming project codenamed "search monkey," which will give third-party users the ability to add images and other data to expand on the information displayed on a results page.

Yahoo Buzz launched today with content from just under 100 publishers. Participating content providers will have an icon they can include on their sites to indicate to readers that they can submit stories to Buzz.

The site will generate a Buzz score for each item, giving proportional weight to several ways that users interact with Web content. In addition to voting and search patterns, Yahoo will also look at how many people are sharing the stories with their friends through an e-mail utility on the Buzz site.

A company spokeswoman told InternetNews.com that there are many additional factors that are part of the Buzz score "secret sauce," and that Yahoo will continue to tweak the algorithm to ensure that Yahoo is aggregating the top stories on the Web.

Yahoo Buzz will also feature icons to link to Facebook, de.licio.us, Digg and other content-sharing sites.

Yahoo Buzz expands on its move last year to create a "featured content" section, where Yahoo editors pulled in third-party content to showcase on the home page.