Looking for a Keyboard Shortcut Manager

Does anybody know of an external software for keeping track of keyboard shortcuts, and maybe even mouse shortcuts?

I would like to be able to visualize which keys/buttons I have unused on my keyboard/mouse, and which keys are currently being used, etc.

Perhaps with a visual keyboard as well kind of like this:

A better shortcut manager is certainly needed.

A spreadsheet-type display would make it clearer which key combos are available for what modes. Since every mode and every panel has its own keymap, you need a very dense display to get them all in there.

A spreadsheet would also make it clearer what keypresses can be usefully duplicated over multiple panels: eg, TAB (as Object/Edit toggle) is useful in both Outliner and 3dView.