keyboard shortcuts on all the major operating systems

For the last couple of months I have been struggling with the keyboard of my beloved MacBook Pro. How often did I click on "Show Keyboard Viewer"? And it still didn't really help on the long run. Today I did some respective "research", and here are the links:

• table of keyboard shortcuts / comparison of  keyboard shortcuts on en.wikipedia.org – that's an amazing document!!!
• Mac OS X keyboard shortcuts on the Apple knowledge base

Some of those shortcuts, that I really love now on my Snow Leopard MacBook:

• "cycle through open … windows of the current desktop" resp. "switch focus to the next/previous window (without dialog)": Ctrl+F4 or Cmd+` (that's the Grave accent key).
•  "show / hide desktop": F11

Today I also screen dumped my the Keyboard Viewer window, printed it a couple of times, and scribbled all the other uses of a key (together with fn, Control, Alt, Command) on it. This will seriously help me learning how to find brackets, curly braces (that I need for perl and ruby), the tilde (that I need for Portuguese and in a shell command line) far sooner.

Update / 2010-06-22:
Yes, on OS X at System Preferences / Keyboard / Keyboard Shortcuts, this is where a lot of nice shortcuts get listed.