When I was in Munich several years ago I visited the town center and
saw the famous clock playing, though I don't remember the schedule.
See  http://www.youtube.com/watch?v=7JMnE2Oza-M

I was also told the Deutsches Museum is worth visiting:
http://www.deutsches-museum.de/index.php?id=1&L=1

Regards,
Eli Shahar