The wedding industry is worth billions a year.
Even if they opt for a minimalist approach, rather than the full Bride-Magazine-$100,000-helicopters-and-marquee event, few couples get married without at least exchanging rings.
Today’s invention is simply a pair of rings equipped electronically so that they glow when brought close together.
These would of course be coded for each indiviual, so they wouldn’t light up in the presence of any other ring.
There is also the option to have a variant fitted subcutaneously -as a kind of physical pre-nup. Finally, call me a hopeless romantic, but how about a version which plays a couple’s favourite tune?