Umbraco, list media files, sort by size

Question

I am working with Umbraco 6 and searching for a way to know what are the "heaviest" medias (pictures) of my site.

I have a media folder per site.

And I would like to be able to list all the medias from that folder, sorted descending by size.

Say

MySiteMediaFolder

video          === 115.5 Mb
restr          ===   4.3 Mb
my.pdf         ===   1.3 Mb
...
small.gif      ===   0.01 Mb