Saddle Bags Lock, not a big fan of it.

[zeus661]

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.

I do have a second key hidden on the bike but not easily accessible.