This is a plugin that turns one (1!) chest into a portable locker. Simply place a gold block under a chest and the chest will be safely stored in the void along with its contents. To access your chest, place a gold block anywhere and right-click it while holding a normal diamond; the chest will replace the gold block, which returns to your inventory.
I wanted to use gold because outside of the watch, nothing uses gold. Sure, you might not always want to walk around with a gold block and a diamond, but it's trading two inventory spaces for the ability to access a chest anywhere!
Right now, everything's stored in memory. For version 1.0, I plan to store chest data in a flat file, but I just wanted to release this as a proof of concept and to gauge reactions.