Strangely enough my search failed to find any mention of this already suggested but I know it must've been... Anywho...
Perceived Issue:
People can of course, fuck yer shit up by breaking into your town / village and wrecking the place. This obviously sets a lot of people back when they lose their precious Q12 Seeds and Q42 Bones.
The smarter ones know to store the really valuable stuff (high Q spare seeds, silk eggs, high Q tools etc...) on alts and log the alts out. That way if they're attacked, they can re-build easily.
Using alts isn't an in-game thing though and n00bs r 2 st00pid 2 dink abut dis (which isn't necessarily an issue so I'm more of the "It'd be nice to not use alts" camp).
Solution:
Being able to have a hidden stash that allows you to store some things in relative safety. Tools that you can use to re-build with, those good seeds etc... This will function in the same way as a cellar. Simply choose the "Hidden Stash" building option and build it. It takes maybe 4 Blocks of wood for support, 10 Tree Boughs for cover and 10 branches for the lid. When it's just been built, it shows as a small little wooden trapdoor in the ground.
A "Hidden Stash" can be built on any dirt terrain (forest, grassland etc...).
Once built, much like a cellar, it needs to be dug-out. Simply right-click to dig. You have to dig out maybe 40 pieces of soil before it can be used.
Once dug-out, you can right-click your trapdoor and it opens just like a cart or boat. It has room for 1 item to be placed inside, such as a chest or basket. Simply place your basket inside (as you would a cart) and you're done!
Hiding the Stash:
You can then right-click the trapdoor and click "Cover". You need 10 pieces of soil to do this as this takes the soil and uses that to cover the stash.
After it's been covered, to find it again, you MUST dig out 10 pieces of soil in the same spot. Doing so uncovers the trapdoor. Once revealed, simply right-click and "Open". This means a "Hidden Stash" could be anywhere. It could be plowed over. It could be built on top of. It could have a tree planted on it. An appropriately coverered "Hidden Stash" acts just like a normal piece of terrain.
To find someone elses stash, you'd have to dig soil out everywhere, so ideally, only the ones who built it will know that it's 5 tiles North of the Rock, 3 steps East of the tree.
For added bonus, they can be marked on a local map (right click trapdoor, select "Mark on Map"). If that map is open while you're walking through that area, the location of the trapdoor is displayed.
Possible Issues:
A custom client might be able to detect them easily.