Litmus: an easy way to test your design in multiple browsers
I found out about Litmus several months ago but forgot about it, and didn’t even write something down. Litmus allows you to check how your web site designs (even your newsletter email designs) look to your final customers.
They have a cheaper version of their monthly plan that provides a 1 week trial for free.
Another cool little tool available from the same Litmus developers is called CSSVista, a Windows application that lets you edit your CSS code live in both Internet Explorer and Firefox at the same time. It works by having a code editor on a vertical pane, and then two frames on the side with the two browsers showing off the design applying the CSS styles live. Very cool stuff.