Change the Identity of a Project in Xcode 4

You may notice that you cannot directly change the identity name in an Xcode 4 project.  The Identity name looks something like "com.yourcompany.yourapp".  In Xcode 3 you could simply edit this textbox, but in Xcode 4 you must rename the whole project.  To do this:

1. In the project contents pane at left, click the Folder icon.
2. Select the top-level blue line representing the project.
3. If you don't have the Inspector pane (right pane) open, click the button to enable it. This is the third button in the "View" toolbar towards the upper right corner.
4. In the Inspector pane, click the little folded-corner paper (file properties) icon.
5. First thing is Project Name. Type in a new one, you will be prompted to rename project content files. I should add, this will leave your old app with the original name in the simulator, so you still need to delete it from the simulator. Also any files you created in the old app bundle will not be brought forward to the new bundle (unless you find them in Finder and move them over).

source: http://stackoverflow.com/questions/5043066/change-name-of-iphone-app-in-xcode-4