I have managed to stream my ripped DVD library, which is on an external HD but networked via Nero 8 to my PS3.
The PS3 sees the files and lets me play them as individual files, but will not play the whole film from start to finish as though it was a complete DVD. This I can do on my PC as I use Cyberlink Power DVD player. I can fully interact with the menu screan with this softeware via the PC.
The funny thing is I can play prerecorded DVDs via the PS3, so I would presume there must be the right softeware already installed to watch the DVD files (VOB).
I believe you need the INFO. file to use the menu screen, but this does not show up when one looks in the Video_TS folder.