Gantt charts are great for project management, if only because they help you recognize which projects are doomed and which have promise. (These charts were made by Jon Ippolito with the open-source Ganttproject software.)
A doomed project
Task titles
Titles are not organized in outline form.
Titles are vague--could apply to any project.
Task lengths and order
The same contributor has many tasks that overlap.
Promotion begins too late in timeline.
Task completion dates don't line up with milestones.
Overall shape
No dependencies are indicated.
The project proceeds by steps instead of stages, so hard to evaluate in midstream.
The predominant curve is concave down, so not enough leeway for task overruns.
Progress to date
The black line lags the red "today" line, so the project is behind schedule.
A promising project
Task titles
Titles are organized in outline form.
Titles are specific.
Task lengths and order
The same contributor has few tasks that overlap, and different contributors are indicated by different colors.
Promotion begins well before the launch date.
Task completion dates line up with milestones.
Overall shape
Arrows indicate dependencies.
The project proceeds by stages instead of steps, encouraging evaluation in midstream ("release early and often").
The predominant curve is concave up, leaving plenty of leeway for task overruns.
Progress to date
The black line leads the red "today" line, so the project is ahead of schedule.
Why do I want a concave up Gantt chart?
Even if you start out concave up, you're pretty much guaranteed to waste time in the early phase of the project.
That means cutting corners at the end of the project, which means a crappy project and/or life.
Start out with a concave up, and at least you have a shot at pacing yourself better through the timeline of the project.