In the era of digital photography and Photoshop, the use of filters in photography has declined. Some effects of photographic filters can be simulated in post-production software.
Polarization is not one of those things. I use a polarizer in my own landscape and (to some extent) wildlife photography quite heavily. (Links to that work can be found at The Treks of Phyz.)
This video recently bubbled up at Digital Photography Review (my favorite resource for digital camera news and reviews). It's a photographer's description and demonstration of polarizers. Nicely done, and it can certainly act as a springboard for the discussion of polarization in the classroom.
Take a look for yourself.