One embodiment of the present invention provides a system for obtaining an electronic signature from a browser. Exemplary nano-particles are selected from the group consisting of particulate nano-silica, nano-alumina, nano-zinc oxide, nano-boron, nano-iron oxide, and combinations thereof. A fuel gas channel connected to a fuel gas supply passage is formed between the first and third plates. When the intermediate result data units stored in the external memory are needed during a subsequent internal data processing a data signal is read from the external memory. The method and system further comprises providing the communication preference data to the call center. The optical mouse also includes circuitry or a processor to detect bar codes and demodulate data encoded therein.