I am managing several projects involving numerous different departments. I would like to show upper management the various time commitments that each of their departments are involved in each project, but at a high level. Any creative ideas other than the simple Gantt chart? High level, easy to grasp...

Hi pgwolfe
The best and easiest way to do this is to set up a central resource pool that feeds all other projects. You can then create a report from one plan showing all resource allocations across all projects.
See Project help screens to see how to set up a central resource pool and share across multiple projects.
Hope this helps.
Tony