An impressive format and provider of free-affordable textbooks is Flat World Knowledge. In the California State University system, we have faculty and students seeking more affordable, yet quality, instructional materials. FWK is one of the resources we are exploring and we have two faculty advocates who have successfully adopted FWK titles for their courses.
Maria Ballesteros-Sola (CSU Channel Islands) and Lisa Grobar (CSU Long Beach) have a wealth of information as to how FWK texts can best be used with students. They even have data regarding student feedback compaign FWK formats to more traditional print formats.
We would be interested in knowing what others are doing (or considering) with Flat World Knowledge titles in their courses.