I think the new SparkFun Thing is cool, so I put together a design for a shield-like board in Eagle.
https://github.com/uChip/ThingShield
There are two board design files.
The ThingShield_Bare is a board outline that you can use as a starting point for your own shield design (sensors, controls, etc).
The ThingShield_Proto is a shield with prototyping space.
Note: These boards are a bit shorter than the Thing board to ensure that the antenna is not too obscured.
You can order the proto shield from OshPark [here .
CAVEATE: I just ordered the boards myself so they have not been tested yet. I’ll report back here as soon as I have determined that the board is functional. Not that there is a lot that can go wrong with it, but Murphy is still with us. 
Have fun,
Chip](OSH Park ~)