jitter object for blur

There aren't really good cpu blurring effects, so you'll have to look at the open gl shaders. There are guassian blur effects there. You won't be able to make things look quite like you're defocusing a camera..thats much more complex than a simple blur because it has to do with depth, but guassian blurs are probably what you're looking for

For an example, go to your max 5 folder, then
Examples->jitter examples->render->slab-helpers->convolution and try out either cf.blur or cf.gaussian.2p

These will be much faster than something you could dream up with cpu..i never got much mileage out of jit.fastblur in terms of really dramatic blurring