Rayleigh Effect: Fill a large Florence flask with filtered water. Aim a laser down the neck of the flask as shown.  A polarizing filter should be placed between the laser and the flask unless you are using a polarized laser.  Add a few drops of fresh silver nitrate and look into the side of the flask and as moving 360 degrees around the flask observe the scattered, polarized light. The silver nitrate must be made fresh just before the demonstration as it starts to combine with minerals in the water over time. The polarized light intensity as you go around the flask may be measured with a light meter.

Pine-sol or powered non-dairy creamer will work in place of the Silver Nitrate, and are more environmentally friendly.  However, they do produce a more complicated scattering pattern because of their larger particle size.  

In the file with the laser manuals there is a Metrologic Laser Handbook and Catalog which has 101 uses for a laser described in it including this demo.