Hi Ben,
I really enjoyed the Outdoor Console episode, I noticed that you didn't include GPS into the cube and that got me thinking that it would be cool to see you do your take on a Reverse Geo-caching Puzzle box.
I've see a few of these published over the net using Arduino but none of them have implemented the raspberry pi or beaglebone black. Also using the RPi or BB it should be relatively easy to make the box speak as well.
I also like the thought of the puzzle box being able to tweat and record the journey it has taken as well as possible recording a photo diary using the raspberry pi camera.
I hope you like this challenge.
Thanks,
J Kirk