καθαρεύουσα vs δημοτική. An audio-visual example
This short extract from the 1959 film «Ο Ηλίας του 16ου» demonstrates the use of καθαρεύουσα in formal settings. You can find a simple transcription in Greek below.
Update 02.01.2010:
Have a look at this example (from the Digital Archives of Greek Television – ERT), a more extreme example of καθαρεύουσα use from an institutional setting (Greek Army), filmed in 1947.
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Nice:) I love those old movies
I have seen a lot in which are using katharevousa in common Greek, and it is always fanny 
))))
This is a great piece. My dad's generation (60-70 yrs old) I've noticed still uses this form of Modern Greek that contains more Kathareuossa than the spoken language today.
That is not an “extreme example” as you put it. My father and uncles still speak that way as do most educated people of their generation. The movie is called “Ο Ηλίας του 16ου” and was not filmed in 1947 but in 1959.