Gossips. They have been always a part of human conversations--and office workers are not exempted from that.To some extent, talking about another colleague may be healthy as this can greatly improve your relationships. However, there will be always a limit healthy gossips.
I'm sure you do tell stories about your colleagues as well, but just what kind are you?
Link: MSN Careers - What Kind of Office Gossip Are You? - Career Advice Article