Abstract: An audio recorder comprises: a microphone for receiving analog audio signals; a removable memory cartridge for digitally storing audio message data entries; and a microcontroller for converting the analog audio signals to digital signals and storing the digital signals in the removable memory cartridge.

Abstract: A system for the storage and retrieval of audio files includes an audio storage and retrieval device and a label with an encoded memory storage address. The audio storage and retrieval device includes a memory for storing a plurality of audio files where each stored audio file corresponds to a unique memory storage address, a decoder for reading an encoded memory storage address from the label, and a control module: i) in communication with the decoder for deriving the memory storage address corresponding to the encoded memory storage address and ii) in communication with the memory for retrieving an audio file corresponding to the memory storage address.

Abstract: A mobile device with color discrimination for producing one of a plurality of pre-determined physical actions when disposed on an action surface includes a body having a set of wheels and a third point of contact with the action surface; means for executing a physical action; a color detection module including a broad spectrum illumination source with a source lens, the illumination source for producing a spot of light on the action surface; a photodetector with a bandpass filter, the photodetector for receiving light reflected from the spot of light and passed through the bandpass filter; a second photodetector with a second bandpass filter, the second photodetector for receiving light reflected from the spot of light and passed through the second bandpass filter; an electronics module including comparator circuits in electronic communication with the photodetectors; and a microcircuit in electronic communication with the comparator circuits and with the means for executing a physical action.