I recently found this site called Serendipity: Plot Twist Generator.
You just click the button and it makes a random plot twist for you to use in your story. These can be simple, like "Without warning, in walks a clumsy geezer." to the ridiculous, "At this point a pirate arrives, bearing cookies."
I've clicked the button lots and have never seen the same thing twice.
This is great if you get stuck in your story. You can click away until something inspires you. It is also useful as a writing game, click once and you have to use the one that comes up.