I think these little gems are the coolest things.  I think they can act as a fun, functional hiding places for some of your more precious items.  Some of these boxes take 5, 10 and sometimes up to 20 different moves to merely open them.

1. 10 Step Japanese Puzzle
2. Indian Cat Puzzle
3. Keepsake Puzzle Box – I own one almost identical to this, love it.  Fun to just disassemble and reassemble.
4. 3 Step Polish Box
5. Large Celtic Design Secret Box
6. 4 Step Japanese Box
7. 5 Move Morrocan Box