With the recent availability of inexpensive wearable sensing technologies, the emergence and of both off-line and on-line digital-storage capacity and an acceptance of personal data gathering and online social sharing (timeline), life logging has become a mainstream research topic and is being embraced by early adaptors. For example, currently we have the ability to gather and store large volumes of personal data (location, photos, motion, orientation, etc.) in a very cheap manner, using an inexpensive smartphone.