The CP-Pack rocks Open Street Map (OSM)
So the kids, some of their friends, and I did the recent OSM street mapping party for San Jose.
We had a phenomenal time – I highly recommend taking your kids if one of the parties comes to your neighborhood. You can discuss crowd-sourcing, GPS units, mapping, landmarks, and all sorts of fun hiking around. The CloudMade staff were awesome and basically my kids got one on one tutorials from the staff and each child got their own GPS unit.
So now my kids edits will live in OSM forever. All the fountains, landmarks, memorials, footpaths that end in fountains, museums, and public toilets (need to change styles to see it) are due to my kids!!!!! How frickin cool is that. And the great part is that my kids can download the data again and use it for whatever they wish.