This is what I've learned about the practice. Don't know how true it is:
"During slavery, blacks have limited opportunities to worship. When they could, even then the masters would still interrupt service and send for certain people. Those people, out of respect for the service, would hold up a finger (usually the pointer- NOT THE MIDDLE ONE) to symbolize two things:
1) They were sorry for interrupting the service and wanted to show respect.
2) They hoped to return in "1" moment (symbolizing the finger)- even though that "moment" usually outlasted the service."
Whether that's true or not, I *Personally* think it's unnecessary, and all you do is draw more attn. (plus crazy looks) to yourself, b/c in reality, who walks around w/ their pointer finger up? But to each his own!
Aw Man! Did I just participate in the hi-jacking of this thread?