Abstract: The present invention provides various methods and apparatus used in connection with steganography and digital watermarking. In one implementation, a method of obtaining information from a network of computers based at least in part on the environment associated with a first computer is provided. An object is presented within the field of view of an optical sensor device. The optical device is in communication with a first computer. The object includes plural-bit data steganographically encoded in the object. The first computer communicates with at least a second computer in the network of computers. Optical data corresponding to the object is acquired, and the plural-bit digital data is decoded from the optical data. At least some of the decoded data and environmental data is submitted to the second computer, which determines which information to send to the first computer based on the environmental data. Many other embodiments are disclosed herein.

Abstract: An air blower comprising a housing having a through passage for air, a blower and a flow sensing device. The through passage has an inlet end and outlet end. The blower is located in the housing and is operable to draw air into the inlet end of the through passage and to blow air out of the outlet end of the through passage. A blower activator is provided which is operable to detect a flow of air into the through passage. The blower activator communicates with the blower to activate the blower when a predetermined air flow into the through passage is detected and to deactivate the blower when less than the predetermined air flow is detected.