easily change the short username in OS X
One of the most common questions users of Mac OS X ask is "How do I change my short username?" Although OS X provides a simple interface -- the Accounts pane of System Preferences -- for changing a user's long name, there's been no easy way to change the short name of an account once it is created. Until now, that is.
ChangeShortName is an easy-to-use utility that does the dirty work involved in changing the short name of a user's account in Mac OS X (versions 10.4.x and 10.3.x). It can also repair some problems that occur when a user has attempted to change their short username manually and done so incorrectly. For safety, it backs up the NetInfo database beforehand.