Imagine you’ve just gotten on an elevator with a friendly stranger. You have precisely one floor to describe your community to them. What would you say? The elevator pitch is a brief sentence that describes what your site is about. Every word counts! Once decided, it can be sliced and diced to form: the tagline the motto the blurb under the logo a convenience redirect “nickname” for the site perhaps eventually the domain name in some form (Due to a variety of practical difficulties with domain names, we prefer to de-emphasize domain name selection. Most sites will retain their topic.stackexchange.com names indefinitely.) Naming is hard — really hard. But if you can come up with a sensible elevator pitch for your community, it’s a great starting point.
This is a very important topic, but only parts of it have been discussed to this point.
Ideas? Be sure to address as many of the above points as you can.