In this paper, we present a technique to record a large set of room impulse responses using a microphone moving along a tra jectory. The technique processes the signal recorded by the microphone to reconstruct the signals that would have been recorded at all possible spatial positions along the array. The speed of movement of the microphone is shown to be the key factor for the reconstruction. This fast method of recording spatial impulse responses can also be applied for the recording of head-related transfer functions.