Copying remote online pictures

[Lacks]

Aside from copyright issues, here's a question that I've been asked by one of my users. A little background first: I'm using CPG as a hosting system, like PictureStage and PhotoIsland, and the people using it (it's in beta, while I'm sorting out little gimmicks like these) are members of a news-related website where one is allowed to add comments to news stories. Said comments can include links and, of course, pictures.
Pictures are mostly deep-linked from their source, resulting in huge bandwidth-load on the server that hosts the picture in question. To prevent this, I've had the request of adding a 'remote upload' to the CPG, allowing for a remote image to be copied to the user's CPG album.

The remote copying utility, I have, working flawlessly outside of CPG... in order to integrate it, I need to:

- create a thumbnail and preview image
- update the database

The second part is what puzzles me most... we're not talking about batch uploads, or FTP, but placing an image (either by means of an intermediate location or directly) into the user's album folder, and updating the database accordingly.

Is there an easy way to achieve an action like this?