The Google Grants program,
currently in beta release, uses Google AdWords to help nonprofits
spread their messages to a wider audience by providing them with free
advertising on Google.com This
program supports charitable organizations that have a strong mission to
help the world and share our philosophy of community service. Typically
these are in areas such as science and technology, education, global
public health, the environment, youth advocacy and the arts.
This includes open source projects and many more.
If you think that you qualify, read the whole news at google code blog.