Simple demo shows the power of a polarizing filter: Digital Photography Review
Amazon.com : Polaroid Optics 55mm Multi-Coated Circular Polarizer Filter [CPL] For 'On Location' Color Saturation, Contrast & Reflection Control– Compatible w/ All Popular Camera Lens Models : Camera Lens Polarizing Filters :
New Carl ZEISS T * POL Filter 52mm Circular Polarizer Filter Made in Japan | eBay
POLAROID 55mm CP-L Polárszűrő | MALL.HU
Amazon.com : Polaroid Optics 52mm 3-Piece Filter Kit Set [UV,CPL, Neutral Density] includes Nylon Carry Case – Compatible w/ All Popular Camera Lens Models. : Electronics
Amazon.com : Sigma EX DG 72mm Wide Multi-Coated Circular Polarizer Filter : Camera Lens Polarizing Filters : Electronics