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I just came across a very useful tool from Microsoft, that allows you to see the URL of your choosing in IE6, 7 and 8. The final release will apparently include support for Firefox and Safari too.
“How many times have you had to debug your web pages on multiple machines running different versions of Internet Explorer? Or had to wait for a slow web service to return renderings of your pages?
You don’t have to do that anymore. Now you can debug your pages on multiple versions of Internet Explorer on the same machine that you use for development.”
Agreed. Very useful, though my favorite for previewing is the link below. Pretty much every browswer on most platforms. All done in Virtual Machines with screenshots for reference:
http://browsershots.org/
You can also preview your website in multiple browsers by downloading a handy tool called Site Butler. http://building-blocks-web-dev.com/site-butler.html
It will save you lots of time when you are working on the structure of your site.