I love to mountain bike...I just hate to drive. Riding the road is a no-brainer; open the door and pedal out.

As far as getting roadies/triathletes to covert to dirt..I've had some luck by offering "Dirt Virgin" clinics. Usually these take place on nice simple jeep roads, double track and gravel paths. Really...the kind of stuff you probably don't even consider *real* mountain-biking. It's difficult to remember (after you've been doing this for awhile) how scary it can be to go off-road.

With 'cross season is looming, you might try promoting your mtb rides as a way to polish some of those technical skills for roadies hoping to race through the winter.

Better potential riding partners (in my experience): cross-country runners, climbers, soccer and/or rugby players. They seem to have more tolerance for adventure/dirt/risk than the strictly-road crowd.