We demonstrate through a pressure sensor matrix, that weight distribution on feet is influenced by body posture. A small cheap carpet equipped with low precision pressure sensor matrix is already sufficient to detect subtle activities and identity of the person on the carpet. By a 0.4 m(2) matrix of 32 x 32, 12 bit pressure sensors, we achieve 78.7% accuracy for 11 test subjects performing 7 subtle activities (open 7 different drawers or cabinet doors) and 88.6% accuracy in recognizing who has performed the activities. We thus see the potential of using a single carpet as a unified approach in houses to detect how inhabitants interact with the furniture without attaching different sensors onto each single furniture.