Abstract: A method and system for collecting and distributing sense-on-demand data is provided. The sense-on-demand data system uses a network of centralized computers and remote units. The centralized computers may be operated by or on behalf of the operator of the sense-on-demand data system, and the remote units may be operated by users of the network. The remote units may consist of a variety of mobile and fixed-location devices, such as cellular telephones, personal data assistants, laptop computers, desktop computers, and stand-alone data sensor units. The system receives requests for information, identifies remote units that are proximate to the location, forwards the requests to the identified remote units, receives responses from the remote units, and provides responses to the requester.