Creating a 'page last updated' snippet ?

Is there a snippet which can be put on each page to tell a visitor the last time that particular page was updated? I’ve had a search around the site and these forums and can’t find anything and to be totally honest don’t know where to start writing my own.

Any clues please?

Thanks, David

Web Server:
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PHP version 4.4.3
MySQL version 4.0.27-standard
Operating System and version Apache 1.3.37 (Unix)

Browser/Client:
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Browser name and version IE 6.0.29
Operating System and version Win XP

David,
breezer made a snippet for that. Take a look here

Excellent - thank you