If you go to the command line in OS X and type:
…it’ll literally invoke the computer’s voice and “say” what you gave it as an argument (in this case it’ll actually say, “Foo”). Very cool stuff; I’ll be tinkering with this as of immediately. Imagine finishing a backup and having it audibly tell you, “Backup complete.”, or tracking the progress of a tool that takes a while. If you do this, for example:
…it’ll actually say, “Ten percent.”
I’m imagining all sorts of mostly useless but very cool applications for this in custom programs. Enjoy.: — Edit: Oh, and yes, you can make it use … “non-standard” language. I just made it say, “You are an asshat.” It’s quite rich. And it’s even got the main George Carlin seven in there too. For bonus points you can make it say, “Your father is a hamster and your mother smells of elderberries.” Yes, much more fun than it should be.