IE dev Tools ... in a toolbar

see
http://blogs.msdn.com/ie/archive/2007/01/09/ie-developer-toolbar-beta-3-now-available.aspx

download at
http://www.microsoft.com/downloads/details.aspx?FamilyID=e59c3964-672d-4511-bb3e-2d5e1db91038&displaylang=en