Decided to try the new 2.70 test build, couldn't find any info on the net for the volume shaders so I just went in and had a play. After a while I got the hang of it, so I decided to put this scene up to help anyone struggling with it. Analyze he file and materials, and just remember the camer can't be within the volume.
CPU only I'm affraid, man do I miss my GPU's LOL
Hope this helps someone