Towels that say 'butt/face.'

Towels that say 'butt' on one side and 'face' on the other, so if you ever use a towel twice, you know which side you should be dealing with. This is a serious issue.

Reverse Google auto-fill.

Auto-fill or whatever-it's-called shows the most common words *after* a word you've typed. But what are the most common words *before* a word I've typed???