image backup system

[EasyTarget]

I was wondering if there's any hack around which would take images from posts and copy them to the site and then change the link to the new host after a specified amount of time has gone by. It seems that many people just use temporary hosts and some of the threads that we have about graphics end up being just threads full of red x's because the images are no longer at the specified url.

Anyways, if there's something like this, could you please link me to it?
Thanks

so like [ img]http://www.test.com/test.jpg[ /img] would then be copied to the forum and say after a week's time or a month's time, whatever, the link in the img tag would change to something like [ img]image_archive/test.jpg[ /img] so that it can be pulled from the local site instead.