IE Developer Toolbar

The IE blog announced last month that after listening to developers feedback (or seeing what Firefox delivered as standard) they have created the IE Developer Toolbar.
  • 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 800x600 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. - Very handy
Though mainly a copy of what FF offer - its well worth the download and handy to have. Plus the ruler feature is pretty handy, and the DOM explorer is a nice way of drilling through your tags and elements to find any problems.