Actually, I think "six-string banjo" is an unfortunate term, because of vagueness.

In this thread I am sure GUEST and the subsequent posters have been talking about what's often called a "guit-jo" or "banjitar", a banjo body with neck and six strings configured a la guitar.

A different animal altogether is what would be a five-string banjo except that it has an additional bass string added between the fourth string and the short thumb string, which would then be the sixth string. This may be played frailing, clawhammer, two-finger pickup, or three-finger bluegrass style. Or I suppose it COULD, if you wanted to, be played plectrum.   This is the instrument that always comes to my own mind when the expression "six-string banjo" is used. I do wish folks would make this distinction plain by their language, and abandon "six-string banjo" to avoid confusion.

Dave Oesterreich