> I use that for journaling: I made a little system that sends me an email every day; I respond to it and the response is then sent to a page that stores it into a db.

Yes. I know note taking and journaling posts are frequent on HN, but I've thought that this is the best way to go, is universal from any client, and very expandable. It's just not generically scaleable for all users, but for the HN reader-types, it'd be perfect.