Well... the link I noted above actually does this... except he uses a creation of a flame upon impact of the drop instead of a splatter...have your read the step by step explanation of how he created the promo video?
Here is a sight that uses a drop to create a wave on impact... all you need to do is add the drop (from a top view... just like the link I originally posted used his drop viewpoint)... and you have what I think is what you are looking for... BUT, you can not rotate over the drop to get the view (i.e., go from a side view to a top view).
http://www.ayatoweb.com/ae_tips_e/ae26_e.html#
As for free... well... Blender is free... you just have to download it... and Blender is a very powerful 3d application that can do what you want...but, it will some time to learn how to use the software. It is not easy to learn in my opinion.
Joe
