Planes: Flying coach for 10.5 hours sucks!
Subways: Very crowded. Throw away any fears about swine flu - if someone has it, you'll get it! And, smelly people will ALWAYS stand near you.
Busses: Cheapest way to get around. The bus that we take will ALWAYS be at 180% occupancy while every other bus you pass will be at 20%. Therefore, plan on standing. There's an art to riding the bus. Since there will never be an open seat, you stand very close to people that have seats. You try to look relaxed, but the entire time you are eyeballing the people with seats and looking for any signs of someone getting ready to get up. If someone is about to get up, you want to be positioned as close as possible to them and attempt to grab the seat when they vacate it.
Taxis: Not so cheap, but more comfortable and quicker. Here's what I learned from my one taxi ride. There are a lot of one way streets down here. And those streets are WIDE - like 8 lanes wide. Even though there are little white lines marked on the pavement, those are just for looks. In the end, the number of "lanes" is equal to as many cars that are willing to drive side-by-side. Machismo rules!
Walking: Be prepared to do a lot of it! The sidewalks down here are ADA compliant - especially if that stands for: ATTENTION, DANGER AHEAD! Those dangers range from major dog droppings, uneven concrete, to just down right holes in the ground.