This is an update to the guide written by Ebay member scurtains who covered the 2nd generation / 2nd gen iPod Nanos here
This covers the 3rd generation/ 3rd gen Apple iPod Nano. Only 4gb and 8gb versions are available. The 4gb IS ONLY AVAILABLE IN SILVER!!! If the iPod you're looking at is Pink, Blue, Black, Green or Red and is advertised as a 4gb iPod, report it to Ebay as a fake item!!! Check the sellers feedback, if they have lots of feedback for selling iPods, as I do, you shouldn't have anything to worry about. If the seller has never sold an iPod before, ask them for the serial number on the back of the iPod. You can go to the Apple website and check it out. Simply go to apple.com, click support at the top of the page then find where it says "check my warranty and repair options". It's somwhere around half way down the page on the right. You can enter the number there. If it comes back giving a Warranty expiration date, all is well. If it says "our records indicate that your product is not covered for service", again, in theory the iPod is genuine but over a year old. If it says anything else the iPod is either not a UK unit or it's not genuine.
Also, nothing to do with fakes iPods, but I've noticed some sellers offering refurbished units. Clearly some people have different views as to what that means. I think of refurbished as meaning fully working and looks like new. Some sellers are offering refurbished iPods that show signs of use. Read the listings carefully people.
Any questions, concerns or points to add, feel free to get in touch. GOOD LUCK!!!