Below is a high-level outline of the steps required to update a live  
application with minimal user intervention ( similar to what Firefox  
and many other apps do ). Even though I might run into difficulties,  
I've got ideas ( and code already in some cases ) for handling steps 1  
to 4. For Step 5, and specifically steps 5b, a solution does not  
spring to mind. One possibility might be using an Apple script and  
calling the Archive Utility ( formally BOM ) but that is only a hope  
at this point.  Other thoughts/solutions/suggestions for step 5b( or  
any noted flaws in the approach - probably )?  TIA--Brian S.

[1] Per user preferences, check for application update on external web  
site.

[2] Assuming an update is available, inform the user of availability  
and ask if they would like to download.

[3] Assuming user requests download, download the file ( presumably  
zipped ) to some temporary directory where it doesn't conflict with  
the running application.

[4] Notify user when download is complete and request permission to  
install new update.

[5] Assuming user requests installation
	(a) move running app to trash
	(b) unzip downloaded app
	(c) move downloaded app to same directory as running app before it  
was moved to trash.
	(d) delete zipped downloaded file - leaving the old app in the trash  
for the user to delete if all goes well.
	(e) launch new app and quit current app