I recently bought a couple dozen BU Jefferson Nickels and this 1980-P jumped out at me. I don't know anything about error coins and wondered if any of you can tell me about it. Take a look at it here: http://www.redshift.com/~akin/jn1980p_error.html
Looks like a small die chip under Jefferson's eye. I don't know of any collectors who would pay a premium for that, but I've seen coins with small blemishes sell for amazing prices on eBay.