I have just spet the last few hours trying to find the flag to use in Terminal to launch an app with the colored outlines around the various view elements to show how they are nested. I know that Matt Gemmell covered it during the Cocoa Face Off session of NSConference 2009 (at about the 13minute mark in the video). Unfortunately I can't actually read what he types and he doesn't speak the exact command. I know it has to be in the Apple docs somewhere but the search system is currently not being of any use. It looks like her just adds -showAllViews YES to the end of the command to open TextEdit but that command has no effect in 10.6.6. I have also tried every other capitalization I can think of as well as using view instead of views. Every command opens TextEdit just fine but doesn't show the colored outlines.