Source - Virtual ISS website
One of the more unusual uses which has been found for the multiplayer first person shooter Unreal Tournament is "Unrealty", a modified version of the game's engine and editor which allows realtors to recreate offices and houses in 3D and then allow clients to wander around the building. Now NASA have taken that one small step further by using the system to show what the multi-billion dollar International Space Station is going to look like when it's finished. Sadly the ISS was not designed with poly counts and clipping planes in mind, and going EVA is a rather tedious affair as your frame rate plummets the second you leave the airlock. The textures are rather washed out in places as well, and I certainly wouldn't want to run a deathmatch in there. But it's certainly an .. interesting application of modern 3D game technology in a completely different context.
If you fancy exploring the final frontier, head over to the Unrealty website to grab a free copy of the client software, and once you've got that installed just download the ISS "locale" file. At 22Mb it's going to take a while to download, so while you're waiting why not check out this little gallery of screenshots of the Virtual International Space Station to give you a taster? Once you're finished downloading the file simply unzip it and then double click on the .uloc file, and the necessary data will be unpacked and copied into the right folders. Now run Unrealty, change the settings from the horrible default 320x240 resolution (if your graphics card can take the strain), and select whichever view of the ISS you want to check out - you can see it as it is now or as it will appear when it's finished, and explore both inside and out. Fascinating, if a little clunky.