I agree with Thrifty. If it is something that you know the person wouldn't want others to know about or discuss, then it is not okay. If it is a harmless update about that person to a friend, then it is okay.
No, it is not okay, it demeans you, it demeans the people you are gossiping about and it really adds no value to anything.
What do I do with something someone has told me about someone?
Forget it as quickly as possible, if I wasn't quick enough to intercept it before it came out of their mouth.