Etsy shop Tyndall’s Polymerclay sells earphone jack accessories shaped like tiny DSLRs. The plugs are based on popular camera models (e.g. Canon 5D, Nikon D90, Nikon D3), and are created from polymer clay for the body and resin for the lens.
The plug itself can be separated from the accessory, allowing it to be used on everything from keychains to necklaces:
You can find them for $12-$18 over on Etsy.
Tyndall’s Polymerclay [Etsy]