Google introduced their web fonts from their font directory, which are open source, and ofcourse, free to use in any web sites!
In this article I looked a little bit deeper, to let you know how you can use them in your websites.
First of all, the web font directory became accesible to public on May 19th, 2010, and curently has 18 families, some sub-families and variants.
I'm the fancy Lobster font!
I'm from the Yanone Kaffeesatz font family