Just register a new one, and never use your old one any more.
Thats not good enough. There needs to be a delete account option.
Indeed unfortunate that this can't be done. Currently people will always be able to find you on this site if you chose your main online handle as a username. At least you didn't pick your full IRL name, as I've seen here before...
usagioku
Deleting account or changing username
Could any of you guys help me?