If you want a place to keep your money or favorite snacks safe from theives, but you want one made of something supremely strong like thin top-grade plywood you are in luck. ThinkGeek has a DIY kit from UGears that lets you build a small combination safe from pre-cut plywood parts.
Once complete, you get a safe with a 3-number combination lock. There are 179 pieces and it take about four hours to build. You can also cut open the optional slot on top to make it into a locking piggy bank. The inside space is 6.1″ x 5.5″ x 4.1″ and should hold a bunch of cookies or change.
No glue is needed and assembly instructions are included. The downside is if anyone really wants your cookies all you need is a big hammer.