I've actually been the fortunate recipient of two. The first one was given to me by Newt after I had my spill during the first GA rally and I believe that bell decided leave me on my way home from the Noreast rally '05. The second one I got from Wojo and that is still on my bike today.
I've heard two stories about the bells. One is the road gremlin thing and the second is that you ring it to remind yourself of fallen riders and to let them know you're thinking of them. I think of it as something similar to the line from "A Good Life" - "Every time a bell rings an angel gets their wings".
I'm not big on superstitions myself but do feel like it's kind of a shared piece of culture (biking is a culture, right?) and since it's given with good intentions I can certainly appreciate and reciprocate that.
