We use the Berimbau in Capoeira.
It's a 1-string instrument that you play by striking the string with the baqueta (it's a stick ?) and it has 3 tones. Buzz (stone lightly touching string), open (stone not touching) and closed (stone touching firmly against the string).
With the Berimbau, you move it close and away from your body to open and close the sound-hole, giving you a wah-wah sort of effect. It sounds cool when done right ?
The stone acts like a fret, almost, except that you only have one ?
Watch this for a better explanation and basic instruction on how to play one:
But then you also get cool people who use it to play the blues, with what looks like a glass as a slide ?
Capoeira itself originated as a dance in Angola (although it was expanded and popularised in Brazil) so the Berimbau is also considered to have originally come from Africa. Here's an African woman playing her Berimbau.
My Capoeira Mestre is building me one. They cost around R450.
