Have you ever heard of The Big Knit? Every year Innocent Smoothies team up with AgeUK to raise funds for the charity that aids elders in the UK.
They need hats to raise funds this year too, so if you have any scrap yarn you have no idea what to do with, feel free to make a few hats for the cause. So far this year I've knitted over 50 hats, just with some random scrap yarn I've collected from finished projects.
You can find more info, like the address where you send your finished hats here.