You can export Keynote slides to a Quicktime file in the appropriate dimensions and embed the Quicktime of your Keynote deck in your blog. Just select File/Export, and follow the prompts. You can use hyperlink controls to allow users to navigate the deck inside of Quicktime. I discovered this technique last night when I was writing an analysis of the 2008 elections for Coastsider.
This is easier, faster, cleaner, and offers more control than exporting to PDF and embedding via Scribd or Docstoc. I especially like Scribd for embedding PDF’s, but this is a better format slide shows than PDF.
It’s cheaper and easier than creating the slides in 280 Slides. 280 Slides is really cool, but this you can do this on your desktop, own an archival copy of your deck, and don’t have to pay for it.
It’s better than using Flash, Scribd, Google or whatever to embed PowerPoint, because you don’t have to use PowerPoint.
And it’s a faster and more space efficient than taking screen grabs and embedding them as JPEG’s, which has been my fallback for embedding Keynote graphics.