You can look at the thread right above this one. I posted a link to an application which does pretty much what is suggested here. The image is encrypted and the client application decrypts it directly to video RAm. It also defeats attempts to copy the decrypted date from video memory, defeating screen capture. But, it definitely ain't free and as soon as someone wants to crack it badly enough, I'm sure it will be cracked as well Your best protection is still a good visible watermark or posting something so lo-rez, no one will want it. A digital watermark can help you prove it's your image if it's stolen - unless they know the trick and remove it. Anyone who expects to make money from their images should probably use all of those techniques. Ditto if you just don't want the stuff stolen, even if there's no money involved. It's a terrible Catch-22 if you want people to see something in it's full glory but want to protect it at the same time. You can't really do both. The coming cure, Microsoft Palladium, 25 years in prison for sharing mp3's etc. really seems like it may be worse than the disease.

"Democracy is a pathetic belief in the collective wisdom of individual ignorance." - H. L. Mencken