Conversation at work:

[Neil] So we store their short username in the database.
[Charles] Yeah. But then again it's only the database, we can always get the full name if we want it
[Neil] But usernames can change
[Charles] Hmmm, you're right. Then again, full names can change too. When you come down to it, names are a really bad way to identify people. What we really need is to ditch names, and have everyone go by an MD5 hash of their DNA.
[Charles] Of course, it'd suck going to a party, introducing yourself as "1825FC..." and trying to remember who "AF43E9611..." is.
[Neil] We could beam names to each other using Palm Pilots.
[Charles] Ah. Good point.