BeeDeeDubbleU - 7:55 am on Jun 28, 2010 (gmt 0)
I suppose it depends on whether the question is applied to HTML/semantics or SEO.
As I understand it, in both cases you can use H1 more than once on a page but for SEO purposes it is probably best to use it once only. When Google's algo sees six or seven H1s on a page, which one does it use to determine what the page content is about?
I saw a Matt Cutts video in which he said that while you could use more than H1 it should be used sparingly. Personally I would have thought that in a situation where you are targeting a specific keyword or phrase then one occurrence would be optimal.
I think it would be logical to assume that the ranking importance of the H1 tag is diluted by using it more than once. Does anyone disagree?