Tie::Hash::MultiValue.pm A simple module implementing a tied class for hashes which can store multiple values per key. It's specifically designed to be used in code that was already using a standard hash and now needs to be able to store multiple items per key. (This is in contrast to Data::MultiValueHash, which creates an object which implements multiple values per key, but handles access via method calls rather than the standard hash interface.) In addition, you can specify that you want only unique items to be stored; you can even supply your own function to make the decision as to what's unique and what's not yourself. See the man page for further details. To install: perl Makefile.PL make make test make install If you are on a windows box you should use 'nmake' rather than 'make'.