Did you set up a Minecraft account for little Johnny only to learn that "JohnAlanSmith" would actually be displayed in game? If so, no worries. Thanks to Minecraft's name-change policy you can now change a player's Minecraft username one time every 30 days.
How?
1.) Visit
http://mojang.com/2.) Click "Account" on the upper right
3.) Click "Log in" on the upper right
4.) Enter the email address and password associated with the Minecraft account you wish you change the name for.
5.) Under "My Games" Locate "Minecraft"
6.) To the right of "Minecraft" you will see the date you purchased the account, and the username.
7.) Click (Change) next to the username.
8.) Enter the username you would like to have. Choose carefully! You are stuck with the name you choose for at least 30 days.
9.) Enter your password to confirm the change. and click "Change Name"
10.) Log in and show off your brand new player name.
** All items will transfer to your new name automatically on the server.