"tap screen to continue"

i've viewed a few demo applications, such as the crash lander one
to try to discover how to one, load an image such as a splash screen upon initializing the application on the iphone, then having the user "tap the screen to continue" for which the app will load into the main screen

it seems like a simple, at least logical, if a then b, as in if the screen is tapped, then goto the main screen/window

how do i go about doing this?
do I (in the interface builder) design an intro Window, then a Mainscreen Window
or do I do this all within one Window and control it all through Code

thanks for your help