First of all, make this page into a sidebar/panel.
And install this userjs.
How to install scripts here
Then when done, load the page and insert the address into the text field, and select either of the three options(source,dom and resources).
What the source option does is post the url's source to the textarea when loaded and closes the page that was opened. Resources does the same except you get a list of external/internal resources used on that page as links below the textarea.
The Dom option however does not grab the sourcecode of the targer page or close the target page. First it loads the page and adds a mousemove event, and sends the tagname of the element mouseovered, plus the attributes that it has.(To stop the inspecting, just tap ctrl key, to start again, hit ctrl key again)
What do you think?