I've been experimenting with PCB design the last few weeks. I'm currently using an Arduino Uno as my Gateway with everything mounted on a breadboard and dupont cables. As it doesn't have the waf factor I promised my better half to make a nice enclosure for it, but for that I had to create a shield. This one is for my NRF24L01+ network. My latest sensors all work on RFM96 with the MySensors Gateway. But as you can order it almost fully mounted I think it's a nice entrance level solution for those who want to start with MySensors without having all the problems I've seen on this forum. You simple mount the shield - maybe solder the radio - upload the code and you're got to go in 10 - 20 minutes.
I think these look very interesting to do with small children may be able to stimulate their curiosity, the current video games are too much influence on children, occasionally the family together to do their own small games is a new experience.