Adobe BroswerLab: Cool tool to compare how your site will look in different browsers

see http://browserlab.adobe.com and the help page

Common problem: you develop a web site and want to see how it will look in other browsers. I have just found this cool tool by Adobe.

You can view 2 screens side by side:
You can select the browsers you want to test:
You can view 2 browsers at onnce, or softly switch between them (overlay) in the Onion Skin mode.