If you and your partner are both into photography and planning to get married, perhaps this idea is for you: weddings rings based on the Leica 50mm Summilux lens. A Japanese couple asked their jewelry-maker friend to create weddings rings that looked just like the focus and aperture ring.
The friend also made a special wedding ring holder shaped like a Leica M3. The rings slide onto the lens just where they belong. You'd almost be sorry you ought to wear the ring instead of keeping it on the Leica M3 ring-holder.

My wife isn't that much into photography, but else I would have loved this idea for myself!
Source:
Petapixel