Here's a wonderful new tool that a friend pointed me to last night. I 
don't believe it has been mentioned on this list, so I thought I'd pass 
it along:

This is a site that allows you to enter the URL to a web page and see a 
screenshot of how it is rendered in various browsers, on both PC and Mac 
platforms. You can view the pages individually, side-by-side, or with a 
slider that allows you to cross-fade between two views.

The service is currently free, but you have to sign up for a (free) 
account with Adobe to access it. So the biggest risk is increased 
marketing email from Adobe.

Dale Trexel
Web Services
University of Minnesota Law School