Hi,

CPAN also has a module called Hash:merge which to quote it's POD "Hash::Merge - Merges arbitrarily deep hashes into a single hash".

Also if you have the perl cookbook see recipe 5.10 on Merging Hashes (if you dont the book, it would definitly be a good one to get)

A quick search of supersearch also throws up this node: Merging Arrays without duplicates.

Hope this helps.
D