Donate blood. If you can, you ought. Fewer people die, and the survivors share your blood type, so you will have more people around who are potential donors for you. It’s win-win. You also get a cookie.
As part of their social media, the American Red Cross site has avatars for download. Most of them are variations on “I gave” and “please give,” but note the avatar to the left. I don’t know about your favorite FPS, but in Team Fortress 2, everyone I kill gets an image of the kill along with my name and avatar. Now with every headshot I can show off my civic spirit, encourage others to donate blood, and taunt my enemies. I am also thinking of changing my spray to one of the “give blood” avatars, to decorate the enemy base.