How to change my name in OSX? I have entered my name with a typo when I first started my MacBook Pro. Now whenever I open iChat or whenever I send an E-Mail the typo is still there.

Where do I change the name?

I have change the name in System Preferences / Accounts as well as the Profiles for Mail and iChat, but the typo still shows up.

Is there a configuration file I can edit directly?
Even easier than that, on Mac OS X you have what is called a "me" card. Which is a special vcard that is tied to your account name and profile picture.
You can open up address book and edit your name and it will mirror that in iChat and everything else.