Our 10 year old plays at FC Witikon
http://www.fcwitikon.ch/
He joined just after we arrived last year, he had Schnuppertraining first, where the trainer assessed his ability, and he has played and trained regularly since. It has also done wonders for his understanding of German and Swiss German. They do have waiting lists, though, I understand.
What is a "pick up" game by the way? Sounds a bit dodgy to me....