Get new posts:
http://www.photoradar.com/forums/search.php?do=getnew
Get daily posts:
http://www.photoradar.com/forums/search.php?do=getdaily
I saved the two links above as bookmarks in Firefox and they work fine. The first will give you all new posts that have been made since your last visit and any unread posts that you didn't open from your last visit.
The second link will give all posts from the last day. Not sure if that is 24 hours from when you hit the link or from midnight of the previous day.
I generally use the first link.