In its never-ending quest to organize the world's information, Google started to digitize old editions from newspapers like Pittsburgh Post-Gazette, St. Petersburg Times, Today's News-Herald and make them available at Google News Archive.
"Today, we're launching an initiative to make more old newspapers accessible and searchable online by partnering with newspaper publishers to digitize millions of pages of news archives. This effort expands on the contributions of others who've already begun digitizing historical newspapers. In 2006, we started working with publications like the New York Times and the Washington Post to index existing digital archives and make them searchable via Google News Archive," explains Google Blog.
The newspapers digitized by Google are available for free in an interface similar to the one from Google Book Search. Unfortunately it's quite difficult to read articles, even though Google automatically detects headlines and centers the associated content.