I think a useful feature for LJ would be an extension of the birthday reminders. Since I read my LJ more religiously than anything else, it'd be a good place for reminders, even of people who maybe don't have journals. It makes me feel bad when I know it's the birthday of an LJ friend that I've never actually met, but I completely forgot about my mom's birthday. A page where I could enter in a few dates and notes, and then have LJ drop a mention of it in among my friends page would be great. Does that make sense? Does it exist somewhere that I don't know about?