You might also find this article about keyboard shortcuts customizing interesting:
Before you start customizing, I suggest you first generate a summary of the default key assignments. To do that, go to Edit > Keyboard Shortcuts and click the Summarize button to create a chart of the default shortcuts.
Shortcuts can be customized for all the menu commands, the palette menus, and the tools. Switch between them using the "Shortcuts for" menu. For application and palette menus you will need to click the triangle to expand the list for each menu before you can see the list of commands.
You can assign more than one shortcut to the same command by clicking the "Add Shortcut" button. If you choose a set of keys that conflicts with another shortcut already assigned, Photoshop will let you know so you can either undo the change, or accept the change and go directly to the conflicting command to re-assign it.
If you choose an F-key shortcut that is already assigned to an action, it will allow you to accept the shortcut, but the action will override the command until you manually go into the action and remove the shortcut assigned to it.
Once you've customized the shortcuts to your liking, you should save your set and generate a new summary. Click the disk button next to the set menu to save the set permanently, otherwise the changes will be lost if you ever need to trash your preferences. Also, when you save the shortcuts you can return to them at any time--useful if you use Photoshop on more than one computer or a computer that is shared with other users. Just copy the *.kys file from the Photoshop CS\Presets\Keyboard Shortcuts folder and take it with you!