This evening, I got Timothy to try out the PI. Showed him the blinking LED. He was not that impressed. He did play with Scratch for about an hour and seemed to have fun. The sound did not work with the HDMI cable. There is a setting to uncomment in the config.txt file that forces the system to use HDMI. That also makes the sound work.
I bought three 8gb SD cards and installed the pi distro on two of them. One of the cards can be for Tim to play around with. The other will be for XDMC.
After I got both cards completely configured, I realized that XDMC has its own distro for the Raspberry pi. So, it was a waste of time to get the SD card setup.
Tomorrow night, I will go back to the maker meetingspace just to see how that goes. Maybe someone can help me make the rocket launcher.