Notwithstanding On distrusting distrust and Reflux on distrusting trust ... I now have GPG set up properly with Enigmail in Thunderbird and can send and receive encrypted emails. You can get it here or here. I've also uploaded it to some keyservers.
I still consider the "web of trust" complete snake oil, and if you sign something for someone else I put very little store by that. But I know how much I trust those I know. And now I have reason for secure communications: our friends in the Church of Scientology. And I can't tell you how much this pisses me off.
(It's somewhat jarring to see the Thunderbird menus — painstakingly made user-friendly for the worldwide Firefox/Thunderbird push — as extended with Enigmail's crypto jargon.)