If you are forever losing your lens caps or are tired of them blowing around on elasticated keeprs, I recently bought a little gadget which clips onto your camera strap and then you can clip your lens cap into it. It is called a HUFA lens cap clip. Website: http://www.hufaholder.com/main.html There are two sizes dependant upon the width of your camera strap.
I am a retired IT professional. I use my spare time by travelling and taking photographs. I love wildlife and history.