I don't know what it is about hoops, and it probably has to do with their versatility that they are always chic, simple and appropriate, but I've really been noticing them as a choice versus a more elaborate earring. Cameron Diaz's look in In Her Shoes always has hoops, and over at Decorno she listed her travel uniform and its accessories. I think they're comparable to pearls in that they can be a simple, yet effective accessory to an outfit.
These are the smallest hoops in a pack of three I got. The largest ones touch my shoulders, and are really only reserved for laughs. I don't car for small hoops, though. I'm silly like that.