On: This massive Google Earth display in Paris includes 48 screens

That problem has actually already been solved for at least 5 years. There are multiple solutions that do all the necessary calculations, among them:

- PC Solution by Matrox http://www.matrox.com/graphics/en/products/graphics_cards/m_...

- Hardware Solution by RGB Spectrum http://www.rgb.com/products/EdgeBlendUnit/