Google was granted an interesting patent on "Customization of Content and Advertisements in Publications" which triggered rumors of Google Magazine service. The Google Magazine service might offer users the ability to customize and print magazines from the Internet content along with customized ads(wherever you go Google ads follows you).
The abstract of the Google patent says
A method includes receiving personalized content from a plurality of content sources. The personalized content is based on user input. The method further includes receiving a personalized advertisement based on user input, and creating a customized publication including the personalized content and the personalized advertisement.
We have to wait and see how Google is going to productize this idea. via TechCrunch