with sand). Another advantage is the usability, because the user knows intuitive how to use the interface by knowing the function of the physical object. So, the user does not need to learn the functionality. That is why the Tangible User interface is often used to make technology more accessible for elderly people. Examples A simple example of tangible UI is the computer mouse: Dragging the mouse over a flat surface moves a pointer on the screen accordingly. There is a very clear relationship about the behaviors shown by a system with the movements of a mouse. Other examples include: Marble Answering Machine by Durrell Bishop (1992). A marble represents a single message left on the answering machine. Dropping a marble into a dish plays back the associated message or calls back the caller. The Topobo system. The blocks in Topobo are like LEGO blocks which can be snapped together, but can also move by themselves using motorized components. A person can push, pull, and twist these blocks, and the blocks can memorize these movements and replay them. Implementations which allow the user to sketch a picture on the system's table top with a real tangible pen. Using hand gestures, the user can clone the image and stretch it in the X and Y axes just as one would in a paint program. This system would integrate a video camera with a gesture recognition system. jive. The implementation of a TUI helped make this product more accessible to elderly users of the product. The 'friend' passes can also be used to activate different interactions with the product. a projection augmented model. SandScape: Designing landscape with TUI. This interface lets the user form a landscape out of sand on a table. The sand model represents the terrain, which is projected on the surface. In real-time the model projects the deformations of the sand. Several approaches have been made to establish a generic middleware for TUIs. They target toward the independence of application domains as well as flexibility in terms of the deployed sensor technology. For example, Siftables provides an application platform in which small gesture sensitive displays act together to form a human-computer interface. For collaboration support, TUIs have to allow the spatial distribution, asynchronous activities, and the dynamic modification of the TUI infrastructure, to name the most prominent ones. This approach presents a framework based on the LINDA tuple space