Yeah, OK, it's a reasoanbly twisted definition of fun, but, well, there you go.
Because it seems a perrennial need, and because someone actually asked me for it, I put together a Devel module, Devel::Size. Reports the actual memory usage of a variable. Involved a bit of grubbing about in the internals, aided a bit by Simon's Extending and Embedding Perl book. (Yes, I can figure out the nastier grubby undocumented bits, but Tim and Simon already have
So, the next time someone asks "How much memory is this using?" you can actually get them a real answer.