This weekend was the Kinderfest. The street leading up to the Brandenburg Gate is blocked off, and lots of stalls, games, rides and other activities for the kids line the streets (like the Fan Mile last year during the World Cup..with less beer)
The Polizei were out in force, and the kids got to sit on motorbikes, in Police vans and cars, wear hats, make badges, and talk on the speakers.
The German Help Service had (Aussie CES) activities for the kids, including this pulley system that they use to rescue people.
Here is the official link