Saw this and tried the following which isn't automated but is one way of doing it.

• First install SEO Quake plugin
• Go to Google
• Turn off Google Instant (http://www.google.com/preferences)
• Go to Advanced search set the number of results you want displayed (estimate the number of pages on your site)
• Then run your site:www.example.com search query
• Export this to CSV
• Import to Excel
• Once then do a Data to columns conversion using ; as a delimiter (this is the CSV delimiter)
• This gives you a formatted list.
• Then import your sitemap.xml into another TAB in Excel
• Run a vlookup between the URL tabs to flag which are on sitemap or vice versa.

Not exactly automated but does the job.

I havent seen any studies but you could create two pages with different meta and see the results. It is hard to be empirical with this I would think as Google now limits it to two lines but ther could be options for A/B studies that you could follow?

If you create the embed code with your link back to the site then you will get the juice.  You cant actually put a link in a graphic as far as I know (yet!) so make sure the Widget code is attractively titled as well so people will actually like to use it along the lines (not saying this is the way to go by the way)

Fabolous Infographic - Visit The Site for More by [Jesse Walker - Uber Infographic Guy](hhttp://www.yourwigglywidgettysite.com / "Jesse Walker - Uber Infographic Guy")

I have never had to do it but there are tools like PowerMapper which is quite pricey for what it does.  Does he actually want a visual one or more like a tree like structure.  This probably more 'doable; by dumpinghte XML into some formatting tool and importing it into HTML.