GraphJam.com is an interesting web-site with potential. It provides graph-construction tools on-line, then users create "pop culture infographs." Web-site visitors can then make comments and vote for the cleverest graphs. Many of the graphs are humorous, many need some thought to understand (a "cheatsheet" is often provided), and be forewarned, some of the graphs are a little off-color. Yet, I like the whole idea...you might challenge your students to create their own "pop culture" graphs...send the best to me for possible inclusion on theis web site.
Some sample graphs from the GraphJam.com web site: