A little course in Vampire Hunting 101 thanks to our friends at ROFLrazzi!
A few notes: This is meant to be a visual guide, as many similar outlets have different voltages. Just because a plug fits doesn't mean it will work. Always double check before you blow up your cell phone/hair dryer/discount lightsaber.
The outlet widely-used in continental Europe is known as the Schuko and varies between countries; Germany's earth connector is on the clips as opposed to France's middle-pin. The ungrounded version is called the Europlug and is becoming more common around the world.
And lastly, this doesn't cover every single country or sub-type of outlet; just the largest lands and most common interfaces.