Hi, I'm D4RK-L3G10N. Most of my contributions are in São Paulo's Metropolitan Area, São Paulo State, Brazil, the biggest city in Latin America and one of the top 10 cities in the world by any definition. I have a couple of contributions also within the state's countryside, though less significant.
I use JOSM to edit the database, because it's just so much more handy to edit the map from your computer, with all due respect to the users that so skillfully use Potlach.
I speak English, Brazilian Portuguese and German, so any users which speak any of those languages can feel free to talk to me regarding any hints about OSM editing, or any question in general. :)