Windows 7 Tip: 
CSSVista is a free Windows application for web developers which lets you edit your CSS code live in both Internet Explorer and Firefox. Now CSSVista will magically cut your screams in to half because you’ll see all the CSS inconsistencies in one window thus allowing you to use your time more efficiently!.
CSSVista is a three-paned editor—one window is a CSS editor, one window the IE 6 preview, and the third is the Firefox preview. Although Microsoft released Internet Explorer 7 ages ago, boatloads of users are stuck with IE 6. Unfortunately, the rendering engine for IE 6 is an odd bird requiring lots of special attention from developers—especially when it comes to creating cross-browser compatible websites.
CSSVista requires the .NET 2.0 runtime and, despite the name, is a free download for Windows XP only.
You can download it here.
Hey thanks for this .. I was using firebug for mozilla .. But always wanted to get something similiar for IE. Now this link is gonna help me lots ..thanks for sharing.
this looks better then firbug.. great find
Extremely useful software. I’ll definitely try this out. Thanks for sharing.