I missed this PBS special when it was broadcast earlier this year, but tonight I got to see "400 Years of the Telescope" at my astronomy club meeting (yes, I do live an exciting life). Narrated by Neil deGrasse Tyson, the one-hour special does a good job tracing the history of telescope technology and its application to astronomy, from Galileo to Hubble (man and telescope) to the next generation of really huge ground-based telescopes now under development. Good stuff for general audiences, with enough "behind the scenes" views and interview segments with astronomers to make it interesting for people like me who already know most of this stuff.
There's lots of great background material on the web site, including a very good teacher's manual called "Glass and Mirrors" with simple demonstrations on how lenses and telescopes really work, using simple lenses as well as pieces of foam and sticks to simulate light rays and explain things like focal points and why images from concave mirrors (and spoons) can be inverted. Good optics materials!