I read a story similar to this in our local paper about a month ago. Someone scuba diving found a point and shoot camera on the bottom of the ocean, recovered the SD card and posted some of the photos in the local paper. The owner of the photos saw it in the paper and came forward, how lucky is that!
Although I would still be gutted if I dropped my 400D in the sea
http://www.theverge.com/2011/11/26/2587599/canon-eos