My wife bought one for me the day she found out what they were. I had it on my Sporty and when I traded it in it got moved to the RK. Same place as most - right floorboard bracket.
Got mine from my brother when I bought my 06 RG on my Birthday. I just moved it to my NEW 09 Ultra. Hangs on left front engine guard where it is attached to the frame. The lowest point I could find on the bike and when looking at the bottom IT IS THE LOWEST THING HANGING.
Trust me they work!!!!!
Superstitious or not, GOD works in mysteriously wondrous ways!
We carry the tradition of pass it along also. When we hand out a bell that person is responsible for providing the next bell to the next new rider to our group.