See references below for original article.

There are a couple ways to change the __MyCompanyName__ value.

Permanently (open terminal and enter):

defaults write com.apple.Xcode PBXCustomTemplateMacroDefinitions -dict ORGANIZATIONNAME "__MyCompanyName__

Alternatively, changing the “Me” card in Address book or going to Project->Edit Project Settings->General Tab in XCode 3.2.3 also work.

References
codza.com, http://www.codza.com/change-mycompanyname-in-xcode-templates