Firstly, since this was not apparent, I'm a Travel Stack Exchange contributor since it was in Area 51. I don't have a company or an organization or even a job right now. I'm an independent traveller hitchhiking around East Asia.
Now over on the Travel site I just came up with what I think is a great little idea for a site competition in the Travel community.
But before I post the idea on our meta over there I wondered if Stack Exchange already has some policy or whatever of supporting per-site contests made and run by the site's contributors.
It surely must have come up before but I haven't succeeded in finding anything yet on Meta.
A few of us including at least one mod are discussing it in our chat room at the moment but I thought I'd dig into the archives here to find out what other SE sites have done before.