Tool to visualize cloud architectures

Is there a good tool to draw diagramms of cloud architectures?

I know pen and paper is a good way, but I need something to use in an开发者_StackOverflow社区 article, so the output should look professional and well rendered.

An example can be found here: http://aws.amazon.com/solutions/case-studies/photowall/

Any good diagramming application will let you do this. Microsoft Visio is a good example. Open Office Draw might also do the trick, although I cannot speak from experience.