“Google has been working with a number of talented font designers to produce a varied collection of high quality open source fonts for the Google Font Directory. With the Google Font API, using these fonts on your web page is almost as easy as using the standard set of so-called “web-safe” fonts that come installed on most computers.”
“The Google Font API provides a simple, cross-browser method for using any font in the Google Font Directory on your web page. The fonts have all the advantages of normal text: in addition to being richer visually, text styled in web fonts is still searchable, scales crisply when zoomed, and is accessible to users using screen readers.”
More information here.