I ran across an ad for a beautiful product tonight and I couldn't resist playing with their interactive website. Takohl makes rings that hinge open to reveal custom messages or gemstone settings.

They are beautiful designs (at least from the pictures) and fit that category of products that I love: mass customized! Jewelry is a natural for this kind of production, because of the "crafted" nature of the products. However, you don't see a lot of mass customization options, despite the growing number of online retailers (ie, BlueNile, The Pearl Outlet, etc). The only example I could think of, besides truly custom boutique shops, was John Christian (the guy who advertises in the airline magazines). This seems to be a great opportunity for differentiation.

I wonder what other product categories could benefit from a mass customization approach. Fine art, perhaps? Check out Little Masters by Rebecca Hull for an example of this. Clothing design? Fabric or wallpaper patterns?

And, who can forget the NikeID program for customized sneakers and watches or custom-printed M&Ms just in time for holiday parties.