I post a picture to caption.
YOU caption it!
After the captioning has generally died down I pick who has the funniest.
Then THEY post a picture to caption.
Then people caption that pick.
And after the captioning has died down the person who posted the 2nd picture picks whose is the funniest, and then THAT person posts a picture to caption, etc.
It's just one long train of happiness.
Let's start!

This story has been brought up here before. It begs captioning.