http://abcnews.go.com/Technology/story?id=2492984&CMP=OTC-RSSFeeds0312

This is an article about some crazy dudes from Canadia (NOT CANADA, people!).  What they did was scan the Mona Lisa with a nifty color laser scanner in order to figure out what it was that Da Vinci did to make it so nifty (i.e. no visible brush strokes or fingerprints).  Read the article.  Look at the pictures.  You will not regret it.  Hopefully.