Duplicate media in multiple user accounts

We have 3 user accounts on our iMac...we share all of our media and photos and don't really care to keep them separate, we were just told that it was best to have separate accounts for syncing iTunes when we purchased the computer. It's convenient in that regard, but it's led to us have duplicates of EVERYTHING, and that's eating up our hard drive space. Same movies, same photos, same music in all 3 places...

Is there anyway to condense these things down to save space and still keep the separate profiles? Or is that just completely defeating the purpose?

Thanks!