My completed artificial star based on a sawn off key chain diode laser.
(http://gallery.orpington-astronomy.org.uk/albums/userpics/10046/ArtificialStar.jpg)
You all laughed at the prototype at Deep Sky Camp but now it's mounted in a proper box with two 1.5v batteries, a switch and a potentiometer for adjusting the brightness. The pin prick of light is slightly less than 0.1mm
See also http://www.oldham-optical.co.uk/Red_Light_Source.htm, from where I got the idea.
Mark
very good.
8)