Ajax Plugin which can make your site look likeYahoo

I am looking for Ajax plugin which can help me in displaying thumbnail images of selected posts on the home page. Once the mouse hovers on the thumbnail page it should give a preview of the post in the box above the image.
If you are not able to get what I am trying to tell then in short I would say that I want my home page to have looks of Yahoo home page where people can get short preview of the post once they hover the mouse on the thumb nail.

If any one has got idea about such plugins then please share it.