How can I create a screen shot with emphasis?

How can I create a screen shot like the above? I am using a Mac.

This can be done in gimp

• Select the oval tool
• Make sure the edge settings are fuzzy
• Select the areas you want to put emphasis
• Invert selection
• Select Fill tool
• Set to color and include alpha settings ("alpha" is transparency)
• And fill the selected area outside the ovals.

The Omni Group (developer of OmniGraffle) has a great free Mac app called OmniDazzle that was created solely for the purpose of highlighting areas of your screen.

It comes with a set of 10+ screen effects that can be activated using keyboard shortcuts, mouse gestures or the menubar icon. For the task you described—"screen shot with emphasis"—the Focal Point, Cutout and Flashlight effects would all work. And you can configure things like border size/color, shading level, etc. in a settings panel. (Other effects of note: Scribble and Zoom, which do exactly what you'd expect.)

I've used/tried Gimp, Photoshop, Pixelmator, Skitch, Aviary and a handful of other methods to handle tasks like the one you described, and so far OmniDazzle is the easiest and most convenient. Skitch would be my #2 choice, but that's a much bigger app with a comprehensive set of capture + edit + upload + share tools — whereas OmniDazzle is small, simple and tailor-made for this task.

Here's a video of the process using Skitch