In the past few years, we have seen a wave of new "smart" consumer products that make everyday places aware of our activities. There are thermostats that adjust temperatures based on occupancy [1], doors that alert us when we forget to close them, and "beacons" that track our indoor locations [2]. With recent advances in sensor technologies and the Internet of Things, every corner of our world is slated to gain some capability of capturing our activity traces.As everyday places become more aware of what we do, an enormous volume of activity traces can be captured and potentially amassed over the long run. Yet the narratives surrounding those technologies mostly focus on short-term gains in efficiency and comfort; few have considered the long-term value of those captured traces. We are concerned that traces will be discarded prematurely, since the perceived risk to privacy easily outweighs the as yet unclear benefits. Thus, it is important to ask: How might we, or rather our future generations, find digital footprints left in a place useful in the long term?