Lenny Zeltser wrote a few days ago, on the ISC handlers diary, about alternative sensors to aid intrusion detection on mobile devices, based on research by Grant Jacoby. Without wanting to ruin the content of the article (and it is worth at least a quick read over), it certainly made me think about just what could also be used in small-medium scale deployments and infrastructures; the number of physical entry attempts to a shared remote site/rack, for instance.