Test Your Webpage In Multiple Browsers
Browsershots is a free online service that tests websites for browser compatibility. It is very simple to use. You enter your website URL, select the browsers you want to test it on, and Browsershots presents you with screenshots of your website on each of the browsers. Browsershots supports lots of browsers in multiple versions on Windows, Mac, Linux, and BSD — some 84 combinations in total. You can also select screen resolution, color depth, whether Java is enabled or not, and the versions of Javascript and Flash you want.
Try Browsershots on the browser acid tests. There are currently three acid tests, and they test how standard compliant browsers are. For example, acid test number 2 should display a smiley face. It works fine in some browsers, but on others the results are pretty dismal.