Full source

Full Source is an Internet Explorer menu extension which displays the source Internet Explorer is displaying, directly from the Internet Explorer object model. This is useful wherever javascript is dynamically writing HTML into the DOM, or where XSLT has been used to generate HTML.

To install, simply unzip the two files, then right click on the .inf file and choose "Install". This will copy the .html file into the Windows directory and register the extension in the Registry. You will need to restart Internet Explorer to see the menu extension.