Prezi

Here is the link for Prezi, an online tool for presentations.  You will have to create an account if you want to use it.

More tips on PowerPoint presentations

Here you can find list of do's and dont's for PowerPoint presentations.

The dont's for PowerPoint

Here you can find Don McMillan's standup on the dont's of a PowerPoint presentation.

The 10/20/30 Rule of PowerPoint

Here you can find Guy Kawasaki's recommendations on the length (10 slides), duration (20 minutes) and font size (30 points) in a PowerPoint presentation.

Here you can find a stream of his pitch. ('Bozo' means 'fool'.)

Lists of three and the rule of three: two speeches

Here you can find the first part of Steve Jobs's iPhone product launch speech.
Here you can find Barack Obama's inauguration speech.
In both of them, please pay attention to the usage of the lists of three and the rule of 3s.
Here is a stream where the rule of 3s is explained among other useful tips on making presentations.