  Numerous smart city testbeds and system deployments have surfaced around the
world, aiming to provide services over unified large heterogeneous IoT
infrastructures. Although we have achieved new scales in smart city
installations and systems, so far the focus has been to provide diverse sources
of data to smart city services consumers, while neglecting to provide ways to
simplify making good use of them. We believe that knowledge creation in smart
cities through data annotation, supported in both an automated and a
crowdsourced manner, is an aspect that will bring additional value to smart
cities. We present here our approach, aiming to utilize an existing smart city
deployment and the OrganiCity software ecosystem. We discuss key challenges
along with characteristic use cases, and report on our design and
implementation, along with preliminary results.
