A mobile communication device is connectable to a memory device that comprises a plurality of memorysectors, wherein at least one application is stored in at least one memory sector. The circuit has a plurality of storage elements connected to combinational logic blocks, each of the storage elements being driven by a clock signal distributed from a clock device; and the method involves substantially maximizing the clock skew in the circuit subject to one or more constraints on the design of the circuit. The polling fields of all the data units in this group are set to indicate a poll request. Furthermore, subscribers can also formulate and define their own custom searches to be run on their behalf to identify the existence of particular content on the website.