Well, it's actually a two-part trend.
First, there is the above-the-knuckle ring. I love this, because you can take a ring that you ordinarily wear on your ring finger, move it over to above the knuckle of your index finger, and voila! A completely new look. The style looks amazing when another ring of the same style/size is worn just below the knuckle of the same finger. I am obsessed! The ultimate ring designed for this style is the Repossi Barbere. Unfortunately, it costs an arm and a leg. I am on the hunt for a knockoff.
The second ring style involves wearing one ring on each of your fingers. I have been eyeing this Maison Martin Margiela ring set for a while, but a cheaper alternative is buying 4 of the same wide band ring, and creating your own set.
Another option is combining the two styles...why not? A couple below-the-knuckle rings here, a couple above-the-knuckle rings there, and you have something totally unique and cool.