Digital Playgrounds 2: More playful projects, for kids, adults, anyone?

After the idea came up it seemed already seemed so obvious that there must be projects out there. But even in the MIT Media Group Life Long Kindergarten not very many projects go into exactly that direction. Here two examples:
A New Playground Experience: Going Digital? by Seitinger, Sylvan, Zuckermann.
An Ecological Approach to Children’s Playground Props also by Seitinger.

These projects are interesting and honest academc research projects, but they do not seem to bail the possibilites digital or digitally enhanced playgrounds could have. But maybe there's much more out there which just can't be found...