My 7yr old is an avid reader and at the moment is enjoying the Hardy Boys series, borrowing a couple of books each week from our library and immersing himself in the adventures of Frank and Joe Hardy. A few days ago, he asked me what Morse Code was, since it had been mentioned in one of the books he was reading and we subsequently spent a great afternoon discovering just what exactly Morse Code was. We got out this fantastic electronics set he was given a few years ago and he built a circuit to make an LED flash on and off with a switch. Luckily he knows how to do that kind of thing.
I printed out the Morse Code for him and explained about dots being short and dashed being longer. We spent some time flashing messages to each other.
After practicing and learning all about it, I found this activity for him the boy scouts website, which he loved also. The boy scouts website looked great. I’m going to have to go back and explore some more. This wikipedia page has a great list of abbreviations which helps to speed things up a bit.