Apple - Tool to transform text to all caps or lowercase

You can set this up as a right click service in automator as @Matthieu Riegler suggested.

Open up Automator.app and create a “Service” with this workflow.

Pay close attention to the checkbox up top, “Output replaces selected test”. After the workflow is in place and saved, navigate to “System Preferences-->Keyboard.” On the left hand side select “Services”. On the right hand side you will see the Service you created, in the example its saved as “UpperCase”. Then give it a shortcut by pressing “Add Shortcut” and give it what you would like. Tested in TestWrangler and TextEdit.

Script used in Automator:

on run {input, parameters}
set upperCaseString to ¬
    (do shell script ("echo " & input & " | tr a-z A-Z;"))
return upperCaseString
end run

I am on Mountain Lion 10.8.5 and for all editable text I can select and right click the text and choose Transformations -> Make Upper Case.

However, it seems this does not work in all applications. TextWrangler for example does not show this menu. All system applications (Finder, TextEdit, Mail, Calendar, etc…) all do.