Numbers: Roman Numerals

Why do movies and some TV programmes use Roman Numerals in the copyright notice at the end? The BBC specifically requires Roman Numerals when they commission shows. Wikipedia says this started as a way for film companies to distibute older films without their age being obvious.

Here's a Roman Numeral Converter that also allows you to test your conversion skills.

And Cecil Adams/Straight Dope explains why clock faces use "IIII" for 4 instead of "IV".