Saddle Bags Lock, not a big fan of it.

[SeaSteve]

I for one due carry and extra keys. I had one made that is flat and I keep it in my wallet and another one that I keep on a separate key ring with my house key on it. I been on rides where the owner has lost or lock there key in a trunk (Valkyrie Interstate) and where stuck.

When I ride with a group we, each, swap a key with another person on the ride. Solves multiple problems at once.

...Oops...Sorry Jeff. I responded before I got all the way to the end.