1. Gesture recognition system for remote controlling a TV using a webcam and low-grade computational equipment, which comprises: a single webcam for capturing video sequence of a user which is composed of video frames, and conveying the same into a hand tracker; hand tracker for receiving said video sequence, inspecting each of said video frames for possible inclusion of a user hand within it, and when the hand is determined to be found in a frame from said video frames, calculating a centroid of the hand, and outputting coordinates of the hand centroid into a trajectory buffer; the trajectory buffer for receiving from said hand tracker each of said hand centroid coordinates, and maintaining in storage at least several tens of recent hand centroids, that altogether define a trajectory of the hand; trajectory segmentation module for continuously inspecting said buffer for possible inclusion of relevant trajectories of at least pre-defined lengths that are suspected to relate to a hand gesture pattern, and whenever a relevant trajectory is detected, extracting a trajectory segment of the same, and conveying it into a gesture classifier; and the gesture classifier for extracting from each received trajectory segment global feature parameters of the same, comparing said extracted global feature parameters with gesture global predefinitions, concluding whether the segment relates to a specific gesture command, and in the affirmative case, transferring the command to the TV; wherein said hand tracker comprises a switch for switching the hand tracker between a color-mode and a motion-mode, wherein during a stationary state the hand tracker is in color-mode inspecting the scene to identify existence of the user hand based on an expected color of the user hand, and upon such user hand identification, the switch switches the hand tracker to a motion-mode for tracking a motion of the user hand by inspecting the scene using a dynamic fusion of both color and motion cues as determined by frame differencing, said hand tracker remains in the motion mode as long as an amount of motion between proximate centroids is determined to be above a motion energy threshold, and furthermore, said motion energy is inspected only within a window which is set around said calculated centroid.