I checked 'use as default' when choosing the default launcher, but now I can't start ADW.Launcher any more
I've installed and set up LauncherPro as a replacement launcher app. How do I reset the phone to use the Android default launcher app?
Go into your Settings -> Applications -> Manage Applications. Find Launcher Pro and select it. Hit the button that says Clear Defaults.
Go to settings, applications, manage applications, LauncherPro and click "Clear Defaults"