~ OOC: SPOILERS ~
The six path's or Pein/Pain, was a jutsu-technique were expendable corpses, attached to chakra transceivers, linked back to a Rinnegan-user, i.e. Nagato.
Whilst the other 5 corpses remained pretty much nameless in both the Anime and Manga plotlines, the apparent puppet leader of the pack, (spikey haired dude who commanded the akatsuki) was in fact Nagato's and Konan's deceased friend, Yahiko, the previous founder of Akatsuki in the Rain village and the reasoning behind Konan's and Nagato's attempt at world domination.
The idea for the Six path's of Pein/Pain derives from the six Buddhist paths of Reincarnation, each body was named after one of the different "paths": Deva, Asura, Human, Animal, Preta, and Naraka. The only common feature shared by these bodies was their bright orange hair and their Rinnegan. Each also had a vast number of body and facial piercings of various shapes, sizes, and patterns (these acted as the transcievers). Each body seemed to serve a specific purpose in battle, such as summoning, repairing, and defensive capability.
Nagato was the 7th Pein/Pain, who controls life and death.
The Current Naruto Shippuden episodes should have covered this if my info's a little sketchy =]