this has been posted before.... but its really neat.
If you think about it.. literally. you can add as many speakers to a stereo system ALL you want. but. we are still only hearing in stereo...
we only have two ears.
The ONLY reason that stereo systems need 5.1, 7.1 etc etc speakers is to make it easier for the stereo system to "simulate" surround sound, and to accommodate different room sizes. If you have a stereo system that analyzes its own sound. you can get surround sound with 2-3 speakers (see: Bose)