You may be interested in Not quite an OO tutorial. I use OO in a very light weight way a lot in Perl. For small scripts I use it as a convenient way of carrying around context when calling various functions to get work done. It pretty much completely avoids the need for global variables and allows me to control coupling between different parts of the code by choosing between using explicit parameters in calls or by passing information in the object as part of the object's context.

My entry point for using OO is more like a few tens of lines than a few hundred!