Two more green things in Colombia

• Electric showerheads. Many houses, instead of having an expensive and energy-consuming housewide system for hot water, simply pipe cold water to all faucets etc. But in the showers you put in a special showerhead that's hooked into the electrical supply. It has a heating element inside that turns on when there's water flowing through, so you get a more or less hot shower. It's not an ideal solution, because you have less control over water temp, but for families who can't afford a big water heater and the monthly expenses it entails, the electric showerhead is a godsend.
• Natural gas cars. While many other countries I know of are in an impasse regarding natural gas-powered gas, in Colombia they're widely available, and it's a standard procedure to modify your car to run on both natural gas and gasoline. All the major cities and many smaller ones have at least one station where you can fill up on natural gas, and even if you run out you just switch your car to gasoline. The system isn't perfect, because modifying the engine entails screwing with its synchronization, which means that you have to alter your driving some to adjust. Also, natural gas doesn't give you as much power, so when you're going up mountains it's best to switch to gasoline, which is done with a little switch on the dashboard. But if a poor, mountainous country like Colombia can get its act together regarding natural gas cars and infrastructure, there's no reason other countries shouldn't be able to. (a side note--natural gas's appeal is mainly that it is cheaper to use and releases less particulate air pollution than do gasoline or diesel. But the carbon dioxide emissions are still the same, so it's not like some environmental panacea to switch to natural gas)