Leo Laporte often talks about scanning of negatives on his talk show. I believe his new updated site allows you to type in what you're looking for, and it will scan the logs for your answer, giving you both a text and audio (video too if available) solution. I remember him also talking about the time needed for such endeavors, and recommending a professional company to do it instead. A billion slides/negatives times ten seconds a shot equals a lot of time