Google Docs has a good tool for creating presentations, but although being an online presentation tool, till now it could not be shared by enbedding on a webpage. But yesterday, Google announced that you can now embed your presentations on any webpage and share them with anyone just like YouTube videos can be embedded on any page.
All you have to do is after the presentation is created, click on the "Publish" button on the top-right and then it will give you an iframe tag which can be added to any webpage like I have done below.
This is a very useful feature and was probably the number one on user request list. Check out the presentation above and also look at the announcement from Google here.