Q: How can I use the Omni Group's OmniDazzle screen effects program in conjunction with playing Apple Keynote presentations?
A: By default, Keynote doesn't play well with other applications, as it intercepts all the keyboard commands. You can, however, convince it to play nicely very easily.
It is very easy to get Keynote to play nicely with other applications. Here's what you need to do:
Open the Keynote preferences. This is in the program menu (or Apple/Cmd ,).
Go to the "Slideshow" tab.
Ensure that "Allow Exposé, Dashboard and others to use screen" is enabled with a checkmark beside it.
That's it! Now you can use OmniDazzle in your Keynote presentations.