Pride rings are one of many symbols of gay pride. They are necklaces holding six aluminum rings, one in each color of the gay rainbow flag. Pride rings come in many styles: gay accessory stores sell them in various sizes, shapes, and materials. You can get pride nuts, pride glass beads, pride triangles... just about anything you can think of.
In high school I wore pride rings every day to show closeted gay students that they were not alone, or to give them someone to talk to. I also wore them because I didn't have a car and I couldn't display a gay pride bumper sticker. When I graduated, I no longer felt I had to be so visibly out and that in the real world people could look out for themselves far better than in high school.
Examples of pride rings can be found at the homo depot: http://www.the-homo-depot.com