If you have downloaded some video and it’s packed in multi-volume archive, you can play the file without unpacking.
This is how you do it in Ubuntu. It should work fine on any linux distribution.
You wil need “unrar” and “vlc” or any other video player.

So, in Ubuntu, open a terminal and install these packages. Skip this step if you have allready installed the “unrar” and “vlc” packeges.
sudo apt-get install unrar vlc

Then issue the fallowing command:
unrar p -inul /example/path/to/Some.Scene.Release/some.sr.r00 | vlc -
What the command does:
unrar = starts unrar
p = outputs the extraction data of the file
-inul = disables error messages
/example/path/to/Some.Scene.Release/some.sr.r00 = path to one of the scene release’s rar files
| vlc – = pipes the output of the extraction into vlc that starts to play the output, and therefore plays the video file that is within the rar files. Don’t forget the ending “-“, or it won’t work. You can use another video player if you want, just replace “vlc” with what you want. I have only tested this with vlc and mplayer.

One bad thing with this trick is that you can only pause and play the file, but not rewind or fast forward.