GooglePresentations
Think PowerPoint but easier and everywhere.
Google still doesn’t have the tight integration that Office does, but for me that’s more than made up for by the ease and access.
Prezi
An excellent tool for creating show-stopping presentations. The software uses vector graphics and takes advantage of that fact to allow near-infinite scalability. What does that mean? Take a look at a Prezi I made about Prezi’s innovative user interface:
(press the play button and wait for it to load. use the mouse or arrow keys to navigate)
My other publicly available Prezis are here.
I always use Prezi now, unless I’m collaborating with people that prefer Google. As a last resort, and in Enterprise situations, I’ll use Microsoft Powerpoint.