The way to do this is by the File Menu:
File/Import/Media select All Files
That VOB files are not shown in the Vegas Explorer is proof enough that Vegas 6 does not officially support VOB files.
But I have to admit that version 6c has not crashed yet editing VOB files while version 6b crashed all the time.
In spite of having read about it on this forum, I learned how to do it the hard way today when a student brought in a home made DVD from her PVR. I tried importing the vob (remember to select All Files *.* or it won't see them) but only got a 1:17 file instead of the 23:30 it was supposed to be.
After beating my head against a wall for a while, the light bulb finally came on :-) File - Import - DVD Camcorder Disc.
You'll need to select the folder that the vob is in and that's it.
Worked like a charm!!!
edit: Vegas creates a new folder inside of the one the vob came from and then makes a duplicate copy of the vob file for it's use. Make sure you have lots of hard drive space :-)
search google for the program "dvdshrink3.2". It will allow you to crop any section of the dvd you want (uncompressed) and gives you VOB files on your hard drive. Then you use the import DVD camcorder Disc in Vegas and it renames the VOB files to mpg and places them in the Project Media tab. Then just drop the mpg files on your timeline and away you go.