Here is http://280slides.com/ -- A web based online presentation making system . Here making slides it as easier as in Normal software,
But great thing i like is -- They are not using flash,
http://280slides.com/ is great web software and this is possible because of new language -- Objective - J and Cappuccino web framework --
Today they have released its framework - http://cappuccino.org/
What is Objective-J?
What is Cappuccino?
Cappuccino is an application development framework written in Objective-J. It's designed for building rich applications that run in a web browser. Cappuccino implements the GNUstep/OpenStep/Cocoa APIs, and builds on some of the best Desktop programming paradigms in existence.
more at -