Hi,

Some people are hotlinking to images on my site. It is not such a problem. But once in a while i clean up all uploaded pictures.

How can i take care that their link shows a default image from my site instead of the normal red cross of not finding a image?

simplest way would be to have a script on the 404 file and parse the requested URI
It should also be possible with .htaccess if you are on Apache

For .htaccess on Apache: http://altlab.com/htaccess_tutorial.html