I used to see the buses in Mumbai and was always owerwhelmed by the sheer number of BEST busses running all over the mega city. One major question that I always wanted the answer of was how they manage the route numbers and source and destination lables that are displayed on buses. Then recently I saw what was the innovation behind that.
There are rolls of printed cloth with all numbers and destinations printed on it. All that remains to be done is to just scroll to the route number and name and run the bus on that route. I bet that its beats LCD and other electronic displays by miles when comes to cost.