Just in case anyone doesn't know about PlanningAlerts.com http://www.planningalerts.com/
There are various ways to get notification of planning applications in the area - e.g. signing up for emails and tweets. But I think RSS feeds such as this
http://www.planningalerts.com/api.php?p ... rea_size=m
are most useful.
(Don't click on this link - put it in a reader such as http://www.google.com/reader)