Where can I find the clear plastic sleeves used to protect DVD's from scratches?

I understand that the DVD's can be played with the covers on.Where can I find the clear plastic sleeves used to protect DVD's from scratches?
If you are in US then you can get it at Walmart, Target, Best Buy, Circuit City etc.Where can I find the clear plastic sleeves used to protect DVD's from scratches?
Any Office Depot like store. Best Buy probably has something. Also COMPUSA or another computer super store. For something like this, WalMart probably has something too. Look online at any of their websites in the computer accessory section.