Here's a picture of a young Obama, and you can see a ring on his finger, and also a bracelet.
The ring has an obvious bulge to it, typical of a ring that has a stone in it. I agree that it's not a school ring, though.
It's obvious that Obama is into bling, though, but it's strange that he doesn't have a flashy watch.
Any idea how old he is in that picture. There are varying opinions around the net.