The attached image shows a student-designed holder for the Circuit Playgrounds. With double-sided tape on the top, the board will stay attached securely, while the design also has a part to support the USB connection. Some may choose not to use the tape and remove the board each use. This was designed to allow students to hold the board connected to the computer, without really touching the board itself.
I've been given permission by Dallin (his name is on the bottom) to share this with the community.
This link will allow you to find the file to download if you'd like to print it for your boards (100% scale, 15% infill, no supports (although, the lip supporting the USB might be better if you do supports), PLA at 205 degrees).