After nearly five years of working with Perl, I must admit, I still cannot grasp when or how to use a hash.

I had the same problem - the concepts just eluded me. What really helped me was roy johnson's node Implementing Dispatch Tables This node in particular was useful, but was not what made it click in my head - but rather the concept of the dispatch table. Im probably not the prson to best explain them to you - I suggest reading Higher Order Perl. HOP started off with just enough information ( which was over my head ) to really get me interested in the problems, which in turn led to a better understanding of the underlying concepts - which is what I really wanted to get at anyway. Anyway - I don't know if this helps, but I certainly connect with the statement above about grasping the concept of hashes. Good luck.