The Sitening Blog led me to the Websites as graphics tool, created by Aharef. It’s a great little tool, which produced the following image:

This is a map of the jamesbooker.co.uk homepage with its associated tags mapped out. Here’s a legend (pulled from sitening.com - hope they don’t mind!)

• blue: for links (the A tag)
• red: for tables (TABLE, TR and TD tags)
• green: for the DIV tag
• violet: for images (the IMG tag)
• yellow: for forms (FORM, INPUT, TEXTAREA, SELECT and OPTION tags)
• orange: for linebreaks and blockquotes (BR, P, and BLOCKQUOTE tags)
• black: the HTML tag, the root node
• gray: all other tags