• Debug javascript
• Examine the DOM tree
• Understand the CSS
• Change the CSS in the browser to see its effect
• See the layout of the page
• Determine the dimensions of page elements
• See the page components and understand the page load process
• View the HTTP headers
• Evaluate javascript expressions and commands interactively
• Use debug write (console.debug) statements to issue debug data
• Add breakpoints
• Profile your page

If you use it, all the time, contribute. Ask your employer to support it.