I was thinking so much about the technical aspects I forgot to mention in my last post that I've changed the design.
I had been using a cropped version of the excellent photo of the clock at the Musée d'Orsay by Yves Lorson pretty much since the site launched back in May 2008. However a while ago Yves changed the license for the photo from a Creative Commons Attribution License to "all rights reserved". I looked in to the matter, and the license which was in place when I made the cropped would continue to apply, but I didn't feel comfortable continuing this situation especially as it wasn't so clear as to how it would affect me using the photo in different ways in the future. I tried to contact Yves, but got no reply. So I've made a new logo using Inkscape, an open source SVG editor.
Let me know what you think of the new logo, or any design ideas.