Hubby has this shower curtain of Pi.
http://www.amazon.com/Pi-Shower-Curt...wer+curtain+pi
You cannot see it in the picture, but the number Pi is in small print all the way across the and down the curtain.

I alternate that one with the Chemical Table of Elements.
http://www.amazon.com/Periodic-Table...le+of+elements

( I buy them because they are EVA vinyl)

Mar