I do a fair bit of web design and my normal set-up on the web is Firefox browser and a screen resolution of 1024*768.
There have been numerous times in the past when I have made a change to a website and it looks great on Firefox and unusable on Internet Explorer, but because I don’t even think of using IE, it stays like that for weeks ’til someone points it out to me. Unfortunately, about 80% of people still use IE so it ends up looking bad for 80% of people.
No longer! I found a site called browsershots.org which allows you to put in your page address and come back 2 minutes later where you can view and download what your page looks like in every browser on every operating system and lots of resolutions. Perfect!