Adobe Browserlab is a web application that allows you to quickly view your website on various browsers without having to install them.
You can select several versions of the most popular browsers: Internet Explorer, Firefox, Safari, Chrome, etc. You can also detect variations in each version according to the operating system in which it's installed (Windows XP, OS X, etc.).
The application makes several viewing modes available (simple, dual, by layers, etc.) along with zoom and measurement tools.
Another attractive option from Adobe Browserlab is the ability to create groups of browsers in order to obtain a preview from each one of the browsers within a concrete set.
To use Adobe Browser lab you'll need to have a free account with Adobe.