Hi, this is a short guide for the construction of a partly blurred clip .
The examp1.avi is the undistorted original clip. First construct a distorted version
of the original clip. This is called examp2.avi. Ive done the distortion with an
effect in Fast Movie Processor called chaos effect. Do a search with www.google.com
for "fmp144.exe" and youll find a download link. 
The next step is to extract just one frame out of the examp1.avi. Load this one frame-
pic into your picture modeller and construct a mask for the parts you want to block out.
Fill this with black colour and the other parts with white colour and save it. I have 
called it mask.tif.
Load the original avi (examp1.avi) into your video editing and cutting software.
Next load the mask.tif and change the duration to the length of the examp1.avi.
Normally the original avi (examp1.avi) will be on the first layer and above it on the
second layer will be the mask.tif totally masking the first layer and so you only see
the masking black and white pic. In the next step add some transparency to your mask using
the chroma key. After setting the white colour to transparent you will see the orignal avi with
a masked region filled with black colour. Export this as a new movie, i have called that examp3.avi
Now clear all existing avis and tifs in the video editor and load the distorted avi 
(examp2.avi) in the first layer and load the examp3.avi in the second layer. Now add
transparency to the black area using the chroma key and produce another movie. I have called
that result.avi and voila that is an avi with a partly pixelated image.
If you want to block your face this is an easy method if your face isnt moving a lot
during the clip. If your are moving you have to combine different masks to get the result.
Some of the more expensive software packages do have some features called motion tracking
o handle such things but i havent seen it in the budget price range.
 