Weeeeeeeeeellll... sorry, but I thought the best image to do this with was a metaball one. I am using a metaball model I made a while ago. for this experiment I animated it for 10 frames ( I know woopdee doo ) I tried to get a realistic motion going so that I could see how well this blurring attempt worked... Anyway, onto the juicy stuff. I rendered the 10 frames to a bitmap sequence, then I deleted the floor and rendered the first 9 frames with an object mask. Now, onto photoshop: I used a batch processing macro I made a while back to quickly chop out the metaballs on the first 9 frames using the object mask as a reference. IE anything white on the mask gets deleted. But, you can do this with the magic wand tool if you wanted. I then aranged the images, frame 10 on the bottom layer, frame 9 on the second. And because each frame is offset a little, and the top ones have the background cut out, you can see how it progresses. (I'll do another one so you can see because I don't have this stage of the project anymore) I then set the transparency of the top 9 layers to 10% and applied a gaussian blur to them, And voila, instant...well not so instant and actually a little bit annoying to set up...motion blur