I decided to order a probable genuine from ebay vs. a larger, less expensive, probable fake. Got a repackaged 2 GB Sony Mark 2 for $12.99 shipped. I know I could have gotten a fake 8 GB for a couple of dollars more, but I didn't want to risk it. Anyhow, it arrived today, and I just tested it - it is genuine. Thanks for the info on how to test.
Will 'watch Family Guy with you and explain the pop culture references you don't understand' for food.