Watermarking pictures

[Anon]

I'm doing a web site for a local artist and he's afraid of getting his pictures ripped off. Is there any way to "water mark" the pictures. For example: show the unwatermarked picture on the web site but when someone tries to download it by right clicking it, they get the watermarked picture?

I also thought about preventing right clicks entirely but that's not a great solution and would like to avoid it if possible.

Any ideas?

Thanks,
Mike

[Anon]

If you show an un-watermarked image on the web, the user can download it. Don't waste time with disabling right-click, it is easily bypassed.

If you use GD or some external image processing software like ImageMagick or X-Nview, you can add text over the image when the user loads it.