The amazing people in and around the mySociety have a new project in test. PlanningAlerts.com allows you to enter an email address, a UK postcode and a region that you want to watch. Any planning applications in that area will end up being emailed to you, as they're updated. When I lived in the Borough of Lambeth, they had a similar service, which also gave community events and the like. The issue with a council-run service is if you live near the boundary of the council, you might miss something across the border.
With most councils not really playing ball, they've taken the approach of screen scraping the data off council web sites. This way they can give a genuinely geographic alert, once they have all the councils covered.
One problem with this is that there's no real qualification of the types of development being planned and alerted. For example, I'd want to know if my neighbour plans to chop down one of the trees in their garden, but I'm not particularly interested in someone chopping down trees a few blocks away. But if someone was planning a huge shopping centre anywhere in my suburb, I'd want to know about it. I can only hope the clever clogs behind this find a way.
Now we need an Australian version. I've long been planning to scrape the Marrickville Council list of development applications and geocode them. Now I think I'll have a go, and the PlanningAlerts.com guys have supplied a reasonable output format, though in Australia we don't have the advantage of such a detailed postcode system.