I'm amazed at what you can get away with if you manage expectations.
You can deliver late. You can over-spend. But only if you manage expectations along the way. Not manage those expectations and I'm equally amazed at how even one stakeholder can inflict serious pain on your project!
How do you manage expectations? Involvement. Stephen Covey has said, "No involvement, no commitment." Wise words for project managers.
In this video Andy Kaufman, PMP, keynote speaker and host of the project management podcast entitled The People and Projects Podcast explains why involvement of stakeholders is so critical, and some practical insights on how to do it.