Not strictly work related but I fitted it into lunch break. Blood donation. Not done it for a while for various medical reasons so I had to go through quite a 'first' time rigmarole, but if they want my tired stuff they're welcome to it. Besides, if it gives me an official excuse to have a Cherry Coke, it can't be all bad.
Didn't realize that only 5% of people bother. Get out there and give!