Freeze Frame for Mac

From Elgebar Studios:

Freeze Frame uses the underlying UNIX power of Mac OS X to make your Mac run more smoothly while undergoing a CPU-heavy process, whether it be arranging loops in GarageBand or applying a filter in Photoshop. Freeze Frame allows you to completely freeze an application, making it use absolutely no CPU cycles. This means the next time you're applying a filter in Photoshop and Mail decides it needs to update right now, you can instantly freeze Mail in its tracks allowing Photoshop to run its process uninterrupted. Freeze Frame's "Focus Freeze" feature allows you to freeze all applications but the frontmost one, leaving all the processor cycles for that one app, and preventing any other apps from hijacking that app's progress.