My very first week here at mental_floss I wrote an article called Periodic Tableware, about how people have taken the periodic table of the elements and adapted the form in interesting ways. Since then, I've run across quite a few more examples. Thanks for the suggestions!
In addition to the previously mentioned State of Kansas Table of Elements, here are a couple more tables used to make political points for science. The Cobb County Table of Elements was created by Loren Williams (who also created the Kansas table) in reference to the Cobb County (Georgia) school board decision in 2002 to place warning stickers on biology texts. The decision was recinded in 2006.
More periodic tables, and less seriousness, after the jump.
Many blocks of the Poetic Table of Elements will lead you to poetry about or inspired by the element. everypoet.com invites you to submit an elemental poem, too!
Periodic tables have been adapted for personal use, too. You can wear a periodic table tie or socks. The Periodic Table Shower Curtain from the mental_floss store can be used as a study aid while spending your time in the bathroom. If you get this to impress your guests, you'll need to be prepared to explain at least a little bit of it!