A long time ago (five months) on a site far, far away (roughly two clicks), a great suggestion was made. Jon Ericson came up with the idea of weekly/fortnightly topic challenges. For those not willing to make the one click that is now needed to get to that post, here's the gist:
Everyone upvotes topics or themes they like.
Each week, the highest-voted suggestion becomes the weekly topic challenge. A meta post is written up giving a brief summary of the idea (with the featured tag, hopefully), and at the end of the week, users who asked or answered one or more questions about that topic are recognized.
Repeat until everyone gets tired of the idea or everyone runs out of suggestions.
Now, we have quite a lot of diverse questions on Puzzling, and we sometimes have unofficial themes affecting pockets of questions within a short period of time (notably password and rebus), so it appears that from time to time Jon Ericson uses Force mind tricks to manipulate people$^2$. But generally we don't have this kind of thing.
Should we have weekly/fortnightly topic challenges? By the way, let's agree to go or not go with the idea as a whole before suggesting specific ones.
And no, nobody is required to participate in the challenges.
$^1$ Yes, I know - Worldbuilding is a very cool site!
$^2$ Disclaimer: To my knowledge, Jon is not a Jedi or a Sith. I think.
(This question is shamelessly copied from Worldbuilding.)