[kyorochan]

Funnily enough I've always heard that referred to as a "coin pocket", but since I live in a country that has barely used cash for the last 10+ years I thought this was very anachronistic and started putting my keys in there.

[rsynnott]

I used to think it was for (old, zippo-style) lighters. But nah, apparently it started off life as somewhere to put a pocket watch.