If you happen to have about six projectors laying around, there's a new open-source project available that comes out of academia for panoramic multi-projector image rendering to have a panoramic visualization system for things like flight simulators and Google Earth.
Nenad Mikša, a long-time Phoronix reader from Croatia, developed PanoVRama along with other classmates for their thesis at University of Zagreb.
As said in this Phoronix Forums posting, "So, what is PanoVRama? PanoVRama is a tiled multiprojector panoramic visualization system developed on Faculty of Electrical Engineering and Computing, University of Zagreb. It consists of 6 projectors that are projecting onto a circular canvas, thus providing a 360 degree panoramic visualization. At first, it was only capable of showing panoramic images and videos, but now it also supports Google Earth/Google Street View navigation and flight simulation using Flight Gear simulator."
In that posting he also shares how PanoVRama works. This implementation actually uses X composite with GL_EXT_texture_from_pixmap support so that this panoramic visualization system effectively acts as a giant compositor while transforming the display into a giant panoramic image. This system is also distributed in that there are three computers with two projectors being powered by each system.
For those that just care what PanoVRama can produce rather than the technical details, see their interesting demo video below. They also employ a Nintento Wiimote for handling controls from this system running Arch Linux.
The code that makes this multi-projector image rendering system work can be downloaded from SourceForge and additional technical details in the aforementioned forum thread.