Google has finally introduced it's online slide presentation application to compete with Microsoft's PowerPoint:

Starting today, presentations -- whether imported from existing files or created using the new slide editor -- are listed alongside documents and spreadsheets in the Google Docs document list. They can be edited, shared, and published using the familiar Google Docs interface, with several collaborators working on a slide deck simultaneously, in real time. When it's time to present, participants can simply click a link to follow along as the presenter takes the audience through the slideshow. Participants are connected through Google Talk and can chat about the presentation as they're watching.

[Official Google Blog] Our feature presentation