1. A system comprising: a memory area associated with a mobile computing device, said memory area storing a centralized catalog of emoticon images for applications associated with the mobile computing device, wherein each of a plurality of subsets of the emoticon images in the centralized catalog is associated with a different one of the applications; and a processor programmed to: populate, by an operating system executing on the mobile computing device, the centralized catalog with the emoticon images received from the applications; detect, by the operating system, an execution context of a user of the mobile computing device; select, by the operating system, one of the plurality of subsets of the emoticon images based at least on the detected execution context; and provide, by the operating system, the selected one of the plurality of subsets of the emoticon images to the user within the detected execution context.