Polarising film

Hi,
I want to try some cross polorasation shots so am looking for a small (6X6 ish) piece of polarising film - know where I can get Lee 239 on line but hoping someone may know somewhere more local , and hopefully cheaper .
I am refering to the technique in a couple of recent magazines - Digital Camera Feb & Digital Photography Dec
DebT
I want to try some cross polorasation shots so am looking for a small (6X6 ish) piece of polarising film - know where I can get Lee 239 on line but hoping someone may know somewhere more local , and hopefully cheaper .
I am refering to the technique in a couple of recent magazines - Digital Camera Feb & Digital Photography Dec
DebT