Want to know how your web pages look in different browsers on various operating systems? Try browsershots.org.
When you go to the site, you'll see the page shown below:
Enter the address of a web page on your site, usually the home page, and then select the browsers and/or operating systems you want to view your web pages on. Submit the page.
Your request goes into a queue and you can see the estimated wait in the queue. It's a good idea to go back the next day. Go back to the site and click the Search link. Enter the web page address and click Go. Your site will appear in the results as shown below:
Click on the url and you should see the page like the one shown below.
It will have thumbnails of your pages in the browser/OS combinations you requested. You can click each thumbnail to view the results online or click the link alongside to download all images in one shot.
Remember that your screenshots aren't stored for ever. As the figure above shows, I didn't go back for 4 days and 12 of my images were scrapped.
If you've fiddled around too much with your site - added JavaScript, html modules, and what not - you'll probably find that it won't look good in many browsers!