CliffordK

What about bicycle cages?

I could imagine building some like little concrete bunkers. Italian Pill Boxes?

The lock, of course, could be the weak link. And, of course, people using them for long-term storage. Are there small padlocks that might be recommended? Mini-U-Locks? Security Cameras? Special "FELONY" warnings?

I'd hate to give a person too great of a sense of security, but it would be nice to be able to lock up all of one's belongings and head down to the beach. Or, if a campground/campsite isn't overly isolated, lock up at night.

Edit:
Thinking about this... SMART CARDS. Lockers are normally locked which prevents animals and people from using them as mini-storage or sleeping in them long-term. And, one can monitor who has access, when, and how much the lockers are being used. If networked, one could even know where empty lockers are.

There is also cell phone blue-tooth access. However, power is often an issue for long distance tourists. In fact, providing electricity and USB inside of the lockers would be a nice touch.