16. A method practiced by a battery-powered mobile wireless communications device equipped with a processor, memory, wireless communication interface, camera and microphone, the device having multiple recognition modes enabling recognition of multiple types of content, the method comprising the acts: initiating one or more stages of a first recognition agent process to recognize audio or image content data captured by the mobile device, the first recognition agent process performing a recognition selected from the list consisting of: image watermark recognition, image recognition, object recognition, facial recognition, barcode recognition, optical character recognition, audio watermark recognition, speech recognition, speaker recognition, or music recognition; receiving detection state data indicating a state of the first recognition agent process in performing the selected recognition; determining a relevance score for a second recognition agent process that the mobile device may run, the relevance score being based on data including at least one data selected from a list consisting of: location, sensor data available in the memory, context, expressed user intent, and user history; determining a cost score for said second recognition agent process, the cost score being based on data including at least one data selected from a list consisting of: memory usage, processor usage, and communication bandwidth; and varying an allocation of processing resources to the first recognition agent process based on at least (a) the detection state data for the first recognition agent process, (b) the relevance score of the second recognition agent process, and (c) the cost score for the second recognition agent process.
16. A method practiced by a battery-powered mobile wireless communications device equipped with a processor, memory, wireless communication interface, camera and microphone, the device having multiple recognition modes enabling recognition of multiple types of content, the method comprising the acts: initiating one or more stages of a first recognition agent process to recognize audio or image content data captured by the mobile device, the first recognition agent process performing a recognition selected from the list consisting of: image watermark recognition, image recognition, object recognition, facial recognition, barcode recognition, optical character recognition, audio watermark recognition, speech recognition, speaker recognition, or music recognition; receiving detection state data indicating a state of the first recognition agent process in performing the selected recognition; determining a relevance score for a second recognition agent process that the mobile device may run, the relevance score being based on data including at least one data selected from a list consisting of: location, sensor data available in the memory, context, expressed user intent, and user history; determining a cost score for said second recognition agent process, the cost score being based on data including at least one data selected from a list consisting of: memory usage, processor usage, and communication bandwidth; and varying an allocation of processing resources to the first recognition agent process based on at least (a) the detection state data for the first recognition agent process, (b) the relevance score of the second recognition agent process, and (c) the cost score for the second recognition agent process. 18. The method of claim 16 that further includes: after initiating the first recognition agent process, receiving first user interest data indicating interest of the user in obtaining a result of the first recognition agent process; and varying the allocation of processing resources to the first recognition agent process based on at least (a) the detection state data for the first recognition agent process, (b) the relevance score of the second recognition agent process, (c) the cost score for the second recognition agent process, and (d) the first user interest data.