I wanted to look at the code of an AppleScript in the Scripts Menu. Normally, I would have to do this by navigating to the script in the Finder and opening it in Script Editor. But I took a wild guess and Option-clicked on the script in the menu, and it opened in Script Editor directly! This makes tweaking my frequently-used scripts really easy.
[robg adds: Amazingly handy, and as far as I can tell, not documented anywhere...]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20050104114016413