Tony-- I found a couple of sites on the web for you that may help in locating folkies in Las Vegas. First try http://radiant.org/enigma/calendar.html for a place called Enigma Garden Cafe. Go to the FAQ page... it sounds like a pretty interesting local folkie/coffeehouse/vegetarian restaurant. Also try www.imagination.org for a guy named Dave Weide. He seems to be the LV folkie guru, I e-mailed him asking for more info, but I guess you could do that directly.
Hope this helps a little, I have had to attend conventions in LV a coupla times, and I can tell you that once you get out of town, there's a great little community of Las Vegas outside the strip that has (and wants) nothing to do with sin city. Great hiking and nature stuff as well-- good luck!