As You can probably guess, the host problems are still bothering me. Once I solve them I will go ahead and add a discussion forum to the blog. We will start small and see how it goes

The only thing that I fear of forums is when users leech on to the site with nothing more than the objective to grate everyone else’s nerves and sanity with their “pi$$ and vinegar” personality and attitudes. As long as forum policing can be managed by both moderators and the users, to keep a civil environment, I would completely support forums.

@John: I am sorry for the delayed reply to your query. A photon sieve is a new concept to me as well. But you can use Excel’s bubble chart to get this effect.

A couple of points:-

Yes to a forum, great idea
I notice one or two images don’t work for me now – have you been too aggressive in your bandwidth restrictions?
Finally, the number spiral is a very interesting idea – I’m a keen photographer and like to explore alternative methods of producing images, such as pin-holes and photon sieves, instead of lenses (see here: http://ca.geocities.com/penate@rogers.com/sieve/photonsieve.html). I wonder if there is a way to modify the spreadsheet to generate a photon sieve pattern?

Keep up the good work