The idea of a spectator is someone that is invulnerable and invisible, being able to fly around without the constraints of the physics and be completely unnoticed by the players. This is very valuable as both an administrative (catching cheaters) and recording tool, allowing non-players to enjoy a match from a distance.
pyspades already has a type of spectator already available via the /invisible and /fly commands, however it is bound to the restraints of the current client/server mechanics.
bcoolface has already released this video showing the potential of smooth and invisible flight.
But what would be the best way to implement this ability?