Just stumbled on a link of a link and found that there is too a “web developer toolbar” for IE. Although (currently) unrated, it seems to provide some useful functionality:

• Explore and modify the document object model (DOM) of a web page.
• Locate and select specific elements on a web page through a variety of techniques.
• Selectively disable Internet Explorer settings.
• View HTML object class names, ID’s, and details such as link paths, tab index values, and access keys.
• Outline tables, table cells, images, or selected tags.
• Validate HTML, CSS, WAI, and RSS web feed links.
• Display image dimensions, file sizes, path information, and alternate (ALT) text.
• Immediately resize the browser window to 800×600 or a custom size.
• Selectively clear the browser cache and saved cookies. Choose from all objects or those associated with a given domain.
• Choose direct links to W3C specification references, the Internet Explorer team weblog (blog), and other resources.
• Display a fully featured design ruler to help accurately align objects on your pages.

But, don’t go and downloading all at once… after all it is still in beta—”Beta 2″ to be exact.