You can disable mouse clicks with javascript but if someone wants an image they can always do a screen shot and save it. If you use a flash slideshow - that pretty much is mouse click proof. You are better using a watermark. But even then if someone wants it they do a screen shot and then use photoshop and clone tool it out. But that would take most of the casual image savers out of the picture ( no pun intended )

Thanks INTcommunications,
I don't know how to disable mouseclicks with javascript but think I will remove the few images that I would prefer to keep under control.
Regards