Programmatically Switching Views in Cocoa Touch
I use presentModalViewController:animated:
to bring up a settings view from my main window's UIViewController
and then when the user presses "done" in the settings view I call dismissModalViewControllerAnimated:
from the settings view (reaching back to the parent view) like this:
[[self parentViewController] dismissModalViewControllerAnimated:YES];
You'll want to explore -[UIView addSubview:]
and -[UIView removeFromSuperview]
. Your base window is a UIView
(descendant), so you can add and remove views to it.