Its Quite simple actually, Just add noise to a layer and motion blur it, Duplicate it 3-4 time, mess around with the blending option and move it around the canvas. Theres probably a more detailed tutorials somewhere on the internet.
The gorilla siggy was actually a very random one, I was just bored and started messing around in photoshop , Turned out pretty nice. The girl in the second rain tag is Yachiru from bleach.More shiz... CC?
Little Big Planet Not a siggy, but had to try this out.
Edit: I won't be using the LBP tag, So if anyone wants to use it just buzz me.