Steve - reply to James about the laser project.

I went to Maplins and talked to one of their technical advisers about lasers. I ended up buying a laser pointer and an aerosol can of 'smoke', so that the beam can be seen. I have in my mind how I want this to work but some experimentation is now necessary with electric motors and gears. Peter A said that you can get a mist maker, used in ponds, which should show up the laser beam (more research!).