Interaction is key in modern web design and one of the tools I’ve found to be very helpful in making a more interactive environment is script.aculo.us
Check out a simple example I put together here. Download > Unzip > Open test.htm in a browser
Whatever vertical you run in, if you are using a landing page, you can probably find something on script.aculo.us which will improve conversion rate.
To get started take a look at the example here and pull it apart and make it work for your offers.