I'm thinking about redesigning my blog and just for curiosity today I tried BrowserShots. It allows you to test any website on 60 different combination of browsers and platforms (35 on Linux, 20 on Windows, 5 on Mac). And as result it takes a screenshot of how the website is rendered.
I tried it with 40 default combinations and in 1 hour (the time after which shots in queue expire) it took 34 different shots, from the latest Safari 3.1, IE8 and FF3 to the older IE4.
I had no visitors with IE 5.5 or IE 4 in the last few months, but 15% of the overall visitors came with IE6, and sometimes they don't see the site I designed it. I'll see if I can find a VM with IE6 to try and debug the problem.
Here is how it looks on IE8. Pretty much the same as in IE7 and FF2 and all the other browsers.