The stylesheet that I used for my recent talk and all the other talks I've given over the past few years is available for use by anyone else under a Creative Commons license. Amanda used it, with some modification, for a nifty talk on Weblogs in the Classroom. The advantage to doing your talk in HTML is that it can be immediately made available on -- or even given from -- the web with hyperlinks [as we see more and more people at conferences with laptops, isn't this useful?], it can be standards compliant, it's available to anyone with a browser, and a quick tweak of the stylesheet gives you the talk in notes format for printing. I also like to think that it's easier to use and easier on the eyes than Powerpoint, but that may just be snobbery on my part. In any case, please avail yourself of it if you think it would be useful to you.