When creating new source files xcode adds comments with your name and company name.
Where do I set my company name for xcode (not the project).
In XCode 4, open up your project. Select the top-most item in the Project Navigator (MyProjectName, 1 target, iOS SDK 4.3 -- or whatever). Open up the file inspector (View->Utilities). In the Project Document section, you should see an "Organization" line. Edit that, and new files that you create will display the new organization name. This is a project setting, hence you'll have to do it for every project.
The Organization Name field is one that's shown in the New Project wizard. Its default value is the value that it was on the previously open project.