The document discusses ideas for improving and innovating the taxi industry. It suggests implementing a transit exchange that allows passengers to pre-summon shared rides in the vehicle type of their choosing. This would offer passengers more choice in service levels, prices, vehicle types, and ride qualities. The exchange could adapt in real-time to customer demand and match passengers going in similar directions dynamically using location-aware cellphones and social networks. The exchange has the potential to reduce traffic and costs while offering more flexible transportation options.