If you want to create very fancy, pretty, professional timelines, gannt chart, etc check out Office Timeline 2010 (or 2012). It is a plug-in for PowerPoint and will save you lots of time creating timelines for presentations.
Check it out here.
My only complaint is that I can’t just go change a date and have the charts update and the table doesn’t seem to be linked to the chart. I do like the charts in Visio better for that type of stuff. For presentations, this timeline really looks nice though without messing with the position of labels a lot.