The Humanitarian OpenStreetMap Team (HOT) has created an activation for the floods in the North of Rio de Janeiro in Brazil : http://wiki.openstreetmap.org/wiki/2011_Rio_de_Janeiro_Flooding
YouMapps has published two imagesover the area to enable support remote OSM mappers to contribute to the disaster recovery effort: http://www.youmapps.org/news/brazil-floods-new-spot-imagery-available
Wherever you are, you can join HOT and participate in the recovery effort by mapping on these images with OpenStreetMap tools !