There is a campaign going on to promote open textbooks. Open textbooks are free, online, open-access textbooks, with a license that will allow anyone to use, download, customize or print without expressed permission from the author.
Open textbooks will use open licenses such as Creative Commons and GNU. You can find out more information about open textbooks at make textbooks affordable. They have download links for current open textbooks and information about joining the initiative and organizing.
There are action steps for students, faculty, administrators and legislatures. You can also download a student organizing toolkit and sign a statement to let Congress know you support open textbooks.