Last year, on the Gaming site, there was an event called Hat Dash, where users earned "hats" for their gravatars by completing certain tasks (analogous to badges). Certain actions would trigger the user receiving a hat, which their gravatar could then "wear". For example, editing a post would yield an editor-themed hat (fedora with pen) to the editor.
This year, SE is expanding the promotion to all sites which choose to participate. This event will run from 19 December 2012 to 4 January 2013.
Individual users who don’t want to participate, don’t want to see hats, and/or are generally anti-hat will have an "I hate hats" option available, just as we had on Gaming last year.
The only visual change to the site itself will be the presence of the hats and the "I hate hats" button in the footer.
So, does Drupal Answers want to participate? Please comment, add answers below, and/or vote this question up or down (up/down votes on meta mean agree/disagree).