Although simple, a good idea (and one that I'm considering jumping on) might be to have the newtonian equation for universal gravitation tattooed upon your shoulder in reference to the famous quote from Sir Isaac Newton himself.
Read somewhere that a rose tattoo on his wife's boobs looked beautiful 30 years ago. Now it looks like a long stemmed tulip.people usually just look at a beautiful drawing of a rose or something and say "hell yes, I should totally tattoo this". lol. Well, I'm against meaningless tattoos, but it's really not the case.