Bogota, Colombia is growing "like a pancake," as Rodrigo Nino, real-estate pioneer, says in the video below. Like other cities around the world, as the population quickly expands, Bogota is expanding outward. All that sprawl leads to traffic congestion (the average commute can take up to 90 minutes) and pollution. A more liveable, walkable city would require building upward, with skyscrapers, but it's hard and slow to get city or bank funding. Nino's solution? Crowdfunding.