EnSol, a Norwegian company patented a solar cell technology that you can use as a thin spray-on film on glass surfaces. There are even plans to include thicker solutions to paint on outside walls.
With the technology tiles can be made that that form an electric network. They would serve to replace large solar panels, especially in industrial environments.
EnSol's film uses
nanocrystal in a transparent composite material - traditional solar panels are based on silicon. But you'll have to wait: The product is only expected by 2016.