Running IE8 on your computer? The included developer tools are great. Need to switch to IE7 mode? No problem using IE8.
But what about IE6, IE5.5, IE5, IE4.01, and IE3? Here is a free multiple installer you can use. And it works! And I performed a virus scan (before and after the install)… no problems detected.
Unfortunately, a couple of my JQuery sites look weird with IE6. I know I know, its not JQuery… rather its the IE6 CSS quirks (among other things… standards compliance… cough… cough…).