Ok, this might be easy..
To present the first view controller modaly :
WelcomeViewController *userWelcome = [[WelcomeViewController alloc] init];
[self.navigationController presentModalViewController:userWelcome animated:YES];
[userWelcome release];
this far everything is fine. But, how to pull a second view controller modaly on this one (in any IBAction)? Do I have to pull in a secondary view controller as the first modal view or is there a more simple solution?