Here's a handy tip for those of you workiing in OS X who may accidentally have discovered what happens when you mash 'control + option + apple + 8' at the same time: :eek:

The issue is due to the OS giving its Universal Acccess keyboard shortcuts priority over any third party applications. If you don't need Universal Access keyboard shortcuts, simply go to System Preferences -> Keyboard & Mouse -> Keyboard Shortcuts and scroll down to Universal Access.
Click the checkbox to turn off all universal access keyboard shortcuts and then you can use them in Photoshop or other apps.

Being an avid user of Expose' features I needed a better solution. Adobe doesn't recognize the F16 key of the extended keyboard, so I remapped the Expose' keys to F14, F15, and F16 using Property List Editor which left F1-13 availble for Photoshop. Link below...skip

http://www.macosxhints.com/article.php?story=20050801052917667&query=remap+keyboard