A computer-implemented method comprising: receiving a parameterless search request, which was provided to a mobile computing device (102,202), for information that is relevant to a user of the mobile computing device; in response to the received parameterless search request, identifying with a digital computer system one or more results that are determined to be relevant to the user of the mobile computing device (102,202) based upon a current context of the mobile computing device; and providing the results for display to a user of the mobile computing device (102,202), further comprising: identifying one or more result categories that are likely to be relevant to the user of the mobile computing device (102,202) based upon the current context of the mobile computing device, wherein the one or more identified results are associated with the identified one or more result categories; retrieving first data that indicates whether the user found result categories previously identified in response to previously received parameterless search requests to be relevant; and selecting a portion of the retrieved first data associated with previous contexts for the mobile computing device (102,202) that are determined to have a threshold degree of similarity to the current context for the mobile computing device, wherein the one or more result categories are identified based upon the selected portion of the retrieved first data. receiving a parameterless search request, which was provided to a mobile computing device (102,202), for information that is relevant to a user of the mobile computing device; in response to the received parameterless search request, identifying with a digital computer system one or more results that are determined to be relevant to the user of the mobile computing device (102,202) based upon a current context of the mobile computing device; and providing the results for display to a user of the mobile computing device (102,202), further comprising: identifying one or more result categories that are likely to be relevant to the user of the mobile computing device (102,202) based upon the current context of the mobile computing device, wherein the one or more identified results are associated with the identified one or more result categories; retrieving first data that indicates whether the user found result categories previously identified in response to previously received parameterless search requests to be relevant; and selecting a portion of the retrieved first data associated with previous contexts for the mobile computing device (102,202) that are determined to have a threshold degree of similarity to the current context for the mobile computing device, wherein the one or more result categories are identified based upon the selected portion of the retrieved first data. identifying one or more result categories that are likely to be relevant to the user of the mobile computing device (102,202) based upon the current context of the mobile computing device, wherein the one or more identified results are associated with the identified one or more result categories; retrieving first data that indicates whether the user found result categories previously identified in response to previously received parameterless search requests to be relevant; and selecting a portion of the retrieved first data associated with previous contexts for the mobile computing device (102,202) that are determined to have a threshold degree of similarity to the current context for the mobile computing device, wherein the one or more result categories are identified based upon the selected portion of the retrieved first data.