Wearables as a group are really coming into their own.
(In fact, my co., FiveBits, will be releasing these per our custom code base & crowd empowering pipeline, in work now - if you know how to make HID drivers from scratch, b.i.t. ; - ))
There is no more dynamic source for inputs than those attached to people and other dynamic objects all day every day. They could be an absolute gold mine for planning data, helping planners really see how those using their cities really use them - from what they do b/c it works to workarounds - Statistical extrapolations & guesswork could be much less nec.
I do not think this is true in the world as it is. We have not done enough to keep this sort of thing from being too scary for many to want to participate. If we want to harness this, we must first work to help foundational, crowd controlled bases come into being and common use. We must also make bases to make excellent, cross-project, system wide use of data - no project exists in a bubble