My sister makes me laugh. All three of us have remarkably (or disturbingly, depending on how you look at it) sense of humor (senses? eh...) - so we're chatting online and she says this, which makes me laugh:

L: there's a jellyfish off the coast of Australia that is so toxic that lifeguards there wear pantyhose all over their bodies to prevent stings
L: and that makes me giggle uncontrollably

Me too!