I've designed the next few boards for the project, but haven't ordered them yet. I've been focused on host boards and useful accessory boards lately, and will get back to modules once a few hosts are set up.
I've finished routing the Teensy 3.1 carrier board:
The idea with the Teensy is that the two ports on the bottom edge of the board use the SMD extra header pins from the bottom of the Teensy, and the other 4 ports use the traditional pins from the outer edge.
For the Raspberry Pi Model B, there is a similar extra port. J4 requires the 8 pin header P5 from the Raspberry Pi to function.
In the accessory department, I have a Splitter, which will convert a dual row header into two single row headers. The second header can be pointed either up or down depending on the part placement.
I also have a part I am calling a Flange. The flange is a pass through port with mounting holes
The mounting holes are 30mm apart and sized for M3. The idea is to allow remote mounting of buttons and LCDs on a project (Think about a 3D printer's front control panel). I actually have ordered some of these. Here is an example of an OLED screen mounted on a piece of Openbeam. I'm not entirely happy that a standoff is needed to protect the pins, but it works for now.
This also goes with the MakerMod cable, which is a 6 or 12 pin Male to Female cable. I'm using Pololu pre-crimped wires for now to make the cables. I also have made a 12 pin to dual 6 pin splitter.