Powerpoint Tip

Just came across a cool PowerPoint Tip for presentations:
When in presentation mode, you can press the letter B and the screen goes blank with a black background, and when you hit w the screen goes white. You can use the arrow keys (or any other key) to bring your presentation back to life, right where you left off. A nice trick, when you want to get the focus off the screen and back on the you (the presenter).