The suggestion to check for "com.android.launcher" is a very good one and I will probably use it if I can't find another non-poll method.
But, I just thought of something...If I create a homescreen widget...:
1) Is there an event that will get triggered when the user goes and displays the homescreen (which causes the widget's icon to display)?
2) And if there is a widget event to detect when the homescreen gets displayed, will this event trigger even if the user is viewing a homescreen page that is different from the homescreen page the widget icon is on?