Amateur radio is often called "ham" radio. There are a variety of stories attempting to explain how this started. I won't attempt to document those stories on my web pages, but a query at any Internet search engine (my favorite is Google!) should provide some answers to that question.
If you are not familiar with this hobby, one requiring a license in order to fully enjoy it, please take a look at the web sites of the ARRL (the USA's national organization for amateur radio), Radio Amateurs of/du Canada (the national organization in Canada), or the Radio Society of Great Britain (UK national organization for amateur radio) for lots of information about this hobby.
I enjoy using digital modes like radioteletype (RTTY) and PSK31 at home, sometimes dabble with Morse code (CW), and will occasionally use a microphone (SSB or FM). I have made contacts through repeaters carried by balloons. I have made contacts with other stations using amateur radio satellites orbiting the Earth - similar to using a satellite phone, but without the huge expense for the calls. I have also spoken with an astronaut on the International Space Station 3 times. Overall, I have confirmation of contact with 142 different countries and territories from around the world. Within the USA, I have confirmation of contact with all 50 states and several territories. I have some "wallpaper" for various accomplishments in this hobby - not a lot, but I'm still having fun.
Somewhat related to my radio hobby, I have a small collection of vehicle license plates with my amateur callsigns on them. Some of the plates are (or were) official plates for my car, others are not official - but manufactured in the same places official plates are. Just in case I forget who I am.... :-)