Is it possible to use google maps transit data to show a publich transit route inside your application rather than sending a user to google maps app? I see that google maps on iphone does it well for switzerland (region i am interested in).
Check http://code.google.com/intl/en/apis/maps/documentation/directions/#TravelModes driving, walking and bicycling are there, but it seems like transit is not available.
Anybody got an idea or workaround?
No, there isn't. Google licenses the data from transit agencies, not many of which licenses the data for use in the API. Some agencies publish their data in Google Transit Feed Spec. There's a list of those agencies, you could pull the data from the provider and parse it out yourself, but that's not available for everyone.