Ah … the delights of developing websites on a PC with three monitors.
Here I’ve got my code in the middle screen, Firefox 18.104.22.168 on my left and on the right: IE6 (top) and IE7 (bottom).
Of course, if I had four monitors then I could have had my Windows Live Messenger and Twitter windows open too!
The attractive red and yellow backgrounds that you can see on the left and right screens I use for debugging, so I can see exactly what is where; in a way that, oddly, white on white doesn’t allow.
I also find Cool Ruler an essential aid when debugging width issues (in IE6).
That’s what I’ve been doing today. Mostly.