How to add new layers to the map?
via haiti.ushahidi.com - Haiti terrain layer is available below Google's layers.
They have used mapbox.com for this, which is paid service. So,
1. How to add map layers from mapbox.com?
2. How to add map layers from any WMS service?
Almost any mapserver has installed WMS service, which serves its map tiles realtime for free. This way you could easily have maps of
from institutional mapservers in your country. Imagine how this free map data could give new context to displayed information, and even possibly predict the upcoming situation - so help in decision making process.