i have a OLD high end yamaha Home theater dvd player. and on it it had the ability when you put a dvd in to it, you could mark or bookmark your favorite scenes in the movie and it would remember them. So for example your watching Conair and really love the fight scene in it you would bookmark it in the begininng of the fight scene and then at the end of the fight scene. And everytime you would put conair into the dvd player, you would have the option of playing your favorite scene or scens. or AS I DID. use it for my own personal trailer when people were over.
I think it would be Sweeeet if that could be incorporated into jriver as well. imagine all our dvd's having bookmarks that are similiar to screencaptures if you will, that when people look at our libraries they have the option to view the trailer\ get a sneek peak of the dvd before they choose to watch it.