The phrase "Crazy Random Happenstance" has been around for years, but brought back to light by the now-popular indie film Dr Horrible's Sing Along Blog, starring Neil Patrick Harris and Nathan Fillion.
"U and jenny wearing the same outfit last nite was such a CRH! LOL!!!"
"Did you see the Jets beat the Patriots? Dude, what a CRH."
Billy: Hey, this is weird. I ordered one frozen yogurt and they gave me two. You don't happen to like frozen yogurt, do you?
Penny: I love it!
Billy: You're kidding? What a CRH! Here.