Using over 7,500 lines of code, hacker/artist Jay Salvat created this surprisingly detailed reproduction of da Vinci's Mona Lisa with nothing but cascading style sheets. It's about as modern as modern art can get.
There are no details on just how he went about recreating the famous piece, but looking at the code there aren't any clever tricks or shortcuts used here. The CSS just specifies the position and color of thousands and thousands of oversized pixels. Tedious, for sure, but it's not like daVinci whipped up the original in an afternoon either.
Update: The CSS image was created using a custom PHP class Jay wrote that's available for download here.