From the SO/SE blog:
Instead of stressing out over the vagaries of the brutal, cut-throat .com domain market and debating the “least worst” domain name options ad nauseam, simply focus on telling the world what your community is about. Don’t even think about the domain name! Give us the one sentence “elevator pitch” for your community. How would you explain your site to a stranger you met on an elevator? It’s about … what, exactly?
[...]
For the forseeable future, don’t even attempt to “Pick a domain name!”. If you ask the wrong question, you’ll just get endless variations of wrong answers. The correct question, the one we should have been asking the community all along, is this:
Tell us what your community is about in one brief sentence!
(With thanks to Isaac at meta.Mathematics.)