Stumbleupon Review of : http://www.microsoft.com/downloads/details.aspx?FamilyID=8e6ac106-525d-45d0-84db-dccff3fae677&displaylang=en
Preview sites (side by side, if so it takes your fancy) in IE 6, 7, and 8; …without the hassle of using virtual machines, multiple real machines, or remote services.
Finally, MS start to ameliorate the long term existential damage done to innocent web developers with their bastard browser (no offence to bastards, or, indeed, rat-pigs).