Here’s a great conservation idea — disappearing shower tile patterns. The thermo-chromic acid on the ink (trust me, its a lot safer than it sounds) lets the flower design gradually wash off the longer heat is applied to it. Its an easy way to figure out you’ve been in the shower too damn long. Better yet, it’s an easy way to prove to your significant other that its time to get out, too. Saving the enviroment, getting enough hot water for yourself — everyone’s happy!