This wiki article on dabbawalas in Mumbai really summarises my wonder and interest in this subject for two key reasons: process efficiency and organic development. As the article states, the efficiency and accuracy of the whole system is truly remarkable, especially when you consider the volumes involved and the sheer breadth of the linkages in place. The addition of the fact that this is effectivel an organicly grown process/system/practice that has developed over years makes this level of efficiency even more jawdropping.
In excess of 175,000 lunchboxes are transported across the city by more than 4500 dabbawalas with an estimated 1 in 6 million error rating. There are a lot of companies in the world who would wish for just any one of their processes to begin to approach that level of efficiency.
Mumbai itself is a fascinating city and is one I would love to go back to and spend more time exploring.