Run a perl style contest.

Pick a coding task, and have a panel of judges rank them on their documentation, code clarity, program structure, and overall performance of thier code (ie. does it do the task assigned, and no more? Does it do it correctly for all cases? Is it testable? Was it tested at all? Did the documentation include the test cases? Is the documentation easy to maintain (eg. literate programming techniques, where the documentation is embeded with the code)?

In short, run a contest on what you want to test: their ability to write "solid, readable code". Use the entries as a talking point for developing better coding style and practices within your department. A lot of the points of style are subjective; but that's entirely the point. You want your developers to understand what kind of code that you expect them to write: giving them examples of what you do and don't like will help much more than saying "just do it, and do it 'right'!"

Just my $0.02
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AC