Here’s another one hot off the press from Wired.com.
Lens cap holder that are actually well located: on your camera strap!
In the winter, late fall or early spring, I do not have an issue about where to place my lens cap since I normally wear a jacket or coat with sufficient pockets. Summer time neither as my shorts pockets are ok.
It is only when I put my jeans on that I find the pockets too tights to easily slip it in.
But wait, if I have multiple lens with different diameters, should I have multiple holders?