I've been doing some work on Agile/Scrum lately and I started thinking about Lean Enterprise from my Six Sigma class. The origins of Lean to a large degree come from work by Toyota and focus on manufacturing, but there are some concepts that can be applied to project management.
One area that struck me was muda, which is typically translated as waste but can mean uselessness. Have you ever had to do something on a project that added no value? I know I've done things like create status reports in 3 different formats for different audiences, even though the content was the same. Then there's the task of trying to create a detailed project schedule during planning even though there are a lot of unknowns. You can make a lot of assumptions, but then you have to go back and change everything when your assumptions turn out wrong. Or putting a status report on a shared folder but also emailing it out to a distribution list.
An Agile project management approach will address some of this, but a lot of organizations don't want to leave their waterfall approach behind. You can still apply lean thinking to a traditional PM approach. The key is to look at the process and eliminate any activities that don't help add value to the final product, things like extra bureaucracy, un-needed features (goldplating), or poor communications. If you need some help, go find your resident Six Sigma Blackbelt.