Over the weekend, I tweeted a question: is anyone using Google Maps or another online mapping service to chart incidents of drug-related violence in Mexico (and/or Central and South America)? The one reply I received was this: Wikinarco.com.
In the screengrab above, I've selected a period of incidents from January through September 2011; I've also selected an option to display the currently-known territory controlled by Los Zetas. The site allows you to view approximate territorial control boundaries for each of the major cartels.
(thanks, @SinkDeep)