I can't remember if it was you I mentioned it to, but I said that I would give the society the link for the 3D film that Durham made for the Royal society exhibition, so here it is:
http://icc.dur.ac.uk/index.php?content=Outreach/RSExpo/RSExpo2009
The 3D is red/green and should work with any red/green glasses that you get hold of. There is also a 2D version to download as well.
On this link you will also find posters that we made for the exhibition about dark matter, the life-cycle of a galaxies and stars and the big bang. None of them are particularly complex as they were designed to be understood by children but they may be able to form the basis of future discussions of the group!