To join DVD files (or any like file type) use Super.

Super is FREE and also alows you to covert a file to almost any file type.

Here is the page with the download link:

http://www.erightsoft.com/Superdc.html

Click on "download and use" or you can read through the seemingly thousands of words informing of its capabilities.

1. I use DVD Decryptor like program to rip the raw VOB files to my harddrive.

2. Then I open Super and click "Join like file types" and add the VOB files that contain the movie. For example, Kung Fu Panda split into about 5 Movie VOBs and then I combined them into one VOB file containing the whole movie.

3. Then I encode the VOB Movie to MP4 Movie at the highest settings and change the resolution manually (by clicking the "More" Box above resolution until I can enter my own reso).

When finished, I ended up with the full MP4 Kung Fu Panda movie in 800x480 at DVD quality conversion at 863.4 MB.

It is really more simple than it sounds. Simply copy dvd, join VOBs, convert to MP4 and copy to N900 and watch it. Trust me, your movies will look just as crisp as on TV. I copied my Kung Fu Panda conversion to my wifes HD2 and it looks just as good as the included Transformers 1 and 2. Very impressive. I may upload a video to Youtube in the future to show the quality of the conversion.