i worked on a website in the latest firefox and then presented it on a machine that just had ie6 (and it looked horrible). is there anyway i can test what it will look like in
Adobe's BrowserLab is a great service if all you need is a screenshot. However, if you need to test the interaction with the site, MultipleIE can install IE6 as well as previous versions (not really necessary, though).
If you're looking for tons of browsers and just screenshot functionality, BrowserShots is another great tool.