I am uploading another of my Clay-Mahler lectures here, namely my public talk on the cosmic distance ladder (4.3MB, PDF).  These slides are based on my previous talks of the same name, but I have updated and reorganised the graphics significantly as I was not fully satisfied with the previous arrangement.

[Update, Sep 4: slides updated.  The Powerpoint version of the slides (8MB) are available here.]

[Update, Oct 26: slides updated again.]