Google News Debuts
Google News displays and categorizes headlinesamassed from news sources all over the world. Google News is "compiled solely by computer algorithms without any human intervention."
The site archives articles "from approximately 4,000 news sourcesworldwide," updates its collection of articles every 15 minutes, and automatically arranges those articles "to present the most relevant news first." Quotes from: http://news.google.com/help/about_news_search.html
If you want tofind out a whole lot more about how Google News actually works, you may consult Chris Sherman's recent SearchDay article http://searchenginewatch.com/searchday/02/sd1002-google-news.html