I love “espeak”. Take some text and speak it—with loads of options. Create a .wav file, customizable speaking speed, change the pitch—it’s just wonderful. Extra fun: You can feed content from a text file to read to you or pipe the output of another program into espeak. For example, “rig | espeak” will cause your computer to speak a random, fake person’s name and address. Why would you do that? Who knows. But it’s cool that you can.