Looking at the current way the ratings are sorted two possible ideas come to mind. The first is add 9 to the total of the ratings for an image then divide by the number of ratings plus one, admittedly this may still favour the older images slightly but the order they are sorted would make more sense. The other idea is a bit like the idea I had for sorting by number of comments ie. after calculating the average rating for an image then divide this by the number of weeks since the image was posted to get the value for sorting.

The Meaning and Purpose of Life is to give Life Purpose and Meaning. http://website.lineone.net/~dave_makin/