Presentation Software Alternatives

Looking for an alternative to PowerPoint?  Most of us are aware of the nearly perfect fit of the ARTstor Offline Image Viewer (OIV) for art history presentations.  Want to work mobile?  Take a more experimental less linear approach?  Prezi along with four other PowerPoint alternatives are reviewed in this PC World article.  While most are perhaps better suited to business, Prezi is worth checking out for your next art history presentation.