'Post this photo on your site' code snippet module

Hello,

I'd like system whereby a bit of text (a code snippet -- presumably javascript) appears next to the various versions of photos on our gallery.

When a user sees a photo and would like to display it on their site, they should be able to copy the code we display and paste that code on their site. That code should be reasonable unintelligle as to what's happening on our server.

It should handle 'authentication', serving up the image, and serve up the specific image version (i.e. size) beside which the code is displayed.

This code snippet idea might be analogous to Google Adsense. Without their JavaScript snippets, serving their ads would be very difficult (note: I did not say impossible, but not easy for the uninitiated).

Then, the follow up is we'd need a way to disallow direct linking to photos like via URL like: http://www.ambercode.com/gallery2/main.php?g2_view=core.DownloadItem&g2_itemId=66&g2_serialNumber=1

In the above case (if I understand correctly), main.php acts of the 'image firewall' (a script that allows access to files not stored under the doc root. This firewall should prevent direct viewing of photos from servers other than ours.

Thank you