As a new OS X user (from the UNIX world), I needed to find all the little keyboard shortcuts out there to do things. You would not believe how long it took me to figure out how to reach the menu bar via the keyboard! So, for all you newbie OS X users, I put together a quick reference guide (PDF, OpenOffice doc) for those magic keystrokes you find out about in bits and pieces here and there.
[robg adds: Many of these are documented here on hints, in Mac help, in various applications, etc., but it's nice to see so many in one spot. I know there are other lists out there like this. If you know of one, please post it in the comments.]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20050420002218816