Sadly enough, it is prevalent all over the South. I grew up in a small town in Texas and my brother's best friend was "Bubba". Of course his given name was Truman and this was in the 60's, so maybe he came out on the winning side of this one.

Several years ago, a woman who worked for me gave birth to twins. I don't remember their given names, but they were called "Bubba" and "Sissy".