Blending to different shapes

Anyone know how to blend from one shape to another?

I’ve got this scene here:

There are a cylinder on the left, a cube in the middle and a cone on the right.

My cube moves back and forth between the cylinder and cone and as well, it changes colour from red, to green and to blue repeatedly.

I want to also change the shape of the cube, starting from the left as a cylinder shape then transforming to a cone shape when it gets to the right side.

Any idea how to blend from a cylinder to a cone?

Something like this?

http://en.wikibooks.org/wiki/Blender_3D:_Noob_to_Pro/Advanced_Tutorials/Advanced_Animation/Guided_tour/Mesh/Shape

I looked again at your question, and I see that it wouldn’t be exactly straightforward to make these keys on a cube. A cylinder->cone would be easy though, and it could be done with a cube with a bit of modeling.

Does it have to be cube shaped in the middle?

Well, not not really, it doesn’t have to be a cube in the middle, but I thought it’s a simple morph like Macromedia Flash.