1. In a system having a server that is operable to communicate with a mobile device over a wireless network, the server including a server application database for storing a copy of data items that are transmitted to the mobile device and a server-based remote search module operable to receive search parameters from the mobile device and use the search parameters to identify one or more data items stored in the server application database that match the search parameters, the mobile device comprising: a memory subsystem, the memory subsystem including a local application database for storing data items for one or more software applications; a communication subsystem operable to transmit and receive data over the wireless network; a processing subsystem coupled to the memory subsystem and the communication subsystem and operable to store and retrieve data in the memory subsystem, to execute instructions stored in the memory subsystem, and to cause the communication subsystem to transmit and receive data over the wireless network; a local search module stored in the memory subsystem and executed by the processing subsystem and comprising instructions operable to cause the mobile device to identify one or more data items stored in the local application database that match one or more search parameters; and a remote search module stored in the memory subsystem and executed by the processing subsystem and comprising instructions operable to cause the mobile device to transmit a remote search request to the server if the local search module cannot identify one or more data items stored in the local application database that match the search parameters, the search request including the search parameters; wherein the server uses the search parameters included in the search request to identify one or more data items stored in the server application database matching the search parameters.