Sensor networks have been gaining popularity with the proliferation of internet and wireless networks. Millions of sensors (physical, Webs and social Webs) are available in sensor networks via the internet around the globe collecting enormous amount of data. Generally, sensors provide information about various aspects of the physical world. They can provide information about weather, traffic conditions, efficiency of data center operation, enable autonomic management of smart buildings, and are being used in numerous mobile applications. Due to the diversity and the number of available sensors, it is practically impossible for the general users to manually define the set of sensors that best meets their application needs. The ability to select automatically and intelligently the best set of sensors to form a high level reusable virtual sensor will create a new class of applications and expand the horizon of numerous current applications. To meet these challenges, we developed the Sensor Composer, a foundation tool in which we treat each sensor as a sharable and reusable entity and assemble these sensors to form higher level abstract sensor based on the user requirements.