One of the key places this problem is really a problem is in the internal data structure of objects. Of course an object can be a blessed just-about-anything, but most people use a hash, and store the object state in there.

In Perl 5 you have 'fields' which can help clean up the problem. I also really like the way accessors are handled in the reformed-perl OO syntax module: (my writeup, authors writeup).