Secure storage
 

When I bike, I always take my mini pump, headlight, tail light and helmet with me.
Sometimes I would like to avoid carrying a backpack. Do any of you have a method of securely storing these items on the bike?

Do you mean when you walk away from the bike?

If so, I don't worry about it. I am more concerned about the bike. My bike is rarely out of my sight or a friends sight for more than a few minutes anyway.