They are by far the most popular choice of name at universalpostoffice.com. And that's out of about 150 choices. I think we, as domain people have it sort of ingrained that unless it's a .com it's crappy, but my experience is that non-domain folk don't really have that perception. I have biologi.st, economi.st and physici.st etc. which although again worthless tlds, I think they'll have their time at least as email addresses. Who knows, in the right hands, economi.st could be one of the biggest sites on the net, dontcha think?
That's why I need site developers to partner with me. I just use the domains for email - the web sites are bare. Shame!