SlideRocket is a Web 2.0 application which integrates enterprise relating features, to allow you to create, manage, share and present online presentations. You can import presentations from offline to online, and you can just as easily export presentations from online to offline.
The entire interface is, dare I say it, gorgeous. It's slick, smooth, gentle on the eyes, and all Flash based so everything works as soon as you want it to. If anything, it actually seems to work better than PowerPoint offline. With all of the features that PowerPoint has, it's a much more economically viable option than buying even a basic version of the Microsoft Office 2007 suite.
You can still share your documents with others, setting permissions on slides and objects within your presentation to make sure others can't screw with your work. Transitions, tables, shapes, Flash plugins, other plugins, audio, themes, text, pictures and themes are thrown in there, making this a highly functional web application.
After using this software for the last day, revising and catching up on university work, involving a lot of PowerPoint deck creation and modification - I can honestly say this is something I would continue using. However, I'd want all of the features but I don't want to pay for it.
Regardless of business structure or employee numbers, there are three tariffs which seem to fit most people for pricing. Free, Individual at $10 a month, and Business at $20 per user a month - which all offer more and more, depending on how much you want to pay. There are plenty of demos of the application available on their website, and much more information lying around the place.
On a closing thought, with the recent news that Office 14, the next version of the Microsoft Office system, will come with a set of lightweight web editions of Word, PowerPoint, Excel and OneNote, maybe this start-up won't be lasting as long as I hope it will.