Karl Dawson has started a neat series of articles on correct markup of the head element in a web page at his ‘That Standards Guy” blog. The first entry covers how to use the DTD, the following entries are expected to cover the other elements.
This is a nice coverage of a niche which has not seen much work, and, judging by the number of sites which don’t include a DTD, its well past its time.
Thanks Karl, I’m glad someone thought of this :)