Update (29/11/13):
We will have hats. For those who don't want to participate, there will be an option in the site footer to disable these.
For a while now StackExchange has had a little winter themed event in December for sites to participate in called Winter Bash.
Basically, users earned "hats" for their gravatars by completing certain tasks (similar 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.
From previous years:
- Users had their entire hat collection on http://winterbash2013.stackexchange.com.
- Individual users who didn’t want to participate, didn’t want to see hats, and/or are generally anti-hat had an "I hate hats" option available..
- The only visual change to the site itself was the presence of the hats and the "I hate hats" button in the footer.
This is totally optional. Should we take part in this? Instead of mass responses, just vote on either of the answers below. We have until Dec 1st to reply, so in a week or so, the answer with the most votes will be the one we go with.