For various reasons, I've never been very happy with my MPhil thesis. Looking back on it now, I tend to feel that it had lot of interesting ideas and ambition, but wasn't really a very good bit of scientific research.
That's partly because "Artificial Life" (or any kind of computer modeling) lives in a gray area between science and "philosophy". It's not quite "science" in the sense at looking at evidence from the world. Yet seems more than "conceptual analysis". It's fun to surf between the two very different worlds with their different requirements and notions of rigour, but easy to fall into the trap of doing neither well. (Especially for me, in those days. :-) )
Nevertheless, that's not the reason that the thesis wasn't online. It was because I only had it in Postscript format which is not all that common outside academia. But now, thanks to PS2PDF.com I have it available as a PDF.
Quite an impressive online conversion given that there were some horribly heavy bitmap diagrams in there. That first blank page was there in the original postscript. Not the fault of the conversion.