We describe a wearable sensor technology that passively records "lifelog" images and sensor readings of a wearer's daily life. The focus of our work is not on aggregating, collecting or networking data as in the usual application of sensors in the Sensor Web, but rather on detecting events of interest to the wearer from a multi-sensor standalone device. These events of interest provide effective cues to allow people to more easily access their autobiographical memories. Early research indicates this technology may be potentially helpful for sufferers of neurodegenerative diseases such as Alzheimer's.