There was a time when you could identify the entire country of Cuba by the "accent" of their CW signals. For whatever reason, probably the popularity of certain homebrew gear designs there, most Cuban CW signals had a characteristic "chirp" due to the frequency shifting a little at the start of each dot and dash. That, and sometimes their average frequency would drift up or down the band, and you'd have to chase them around.

I had a lot of fun with radios as a kid (15--20 years ago). It was so magical to talk all across the world from your bedroom. Then this whole Internet thing happened. ;)