It started with reading a news article about the horrible flesh-eating disease. Wondering how much info the Mac Dictionary would give I looked up that long word "necrotizing fasciitis" and my curiosity just got started. Would Dictionary read it to me?
Yes, Mac will read aloud to you. You can use this feature in Dictionary, Pages, Word for Mac, even news you highlight from Google, other Internet sites, and . . . get this! You can listen to the PMUG newsblog being read aloud to you.

Go to Apple in the menu bar across the top of the screen. Click System preferences, under System click Speech. On the Text to Speech tab, select the Speak selected text when the key is pressed check box. Click Set Key, then press the combination of keys that you want to use to hear the text read aloud. Then click OK. I decided to use Command + S. Now the fun of trying it out, here and there.

Oh, here's more about that flesh-eating disease. Click on Dictionary, choose Wikipedia and type in "flesh-eating disease." Up it comes with medical explanations, photos, and links to further resources. There's even a list of notable people who have been afflicted with it.