I've seen some different washer necklaces, but this one, I'll try. I found the link to Chic Steals from One Pretty Thing's blog.
The first picture is the Washer necklace from Chic Steals and the second is a kit you can purchase from Urban Outfitters. All you need is some grosgrain ribbon and washers from the hardware store. Check out Chic Steals blog for the tutorial. I really like the size of the small washers best and the red ribbon really sets it off.