In their greed, Microsoft has chosen to make their PowerPoint files unreadable by such non-Bill browsers as Firefox.
So I've started posting my PowerPoint files as PDF files.
Click the link below to see the PDF version of the PowerPoint for my science talk at the International Conference on the Fantastic in the Arts in March, 2005:
ICFA science talk, "The Lifebox, the Seashell, and the Soul," March 28, 2005.
Note that you can also find the full text of an early draft of my Guest of Honor talk on writing at the same conference:
ICFA writing talk: "Seek the Gnarl," March 27, 2005.