The Red Rock Campground is a pretty nice spot. Obviously lots of people there will have their partners lined up, but that's the best way I know of to meet people. Other than that, I've met people in the calico basin parking lot, but that was mostly for cragging.
Through MP, works. Sometimes the posts don't read like folks are connecting, but only because we switch to email messages. I think several local, "single" climbers connect via the MP super regularly. Did you say you have ropes and rack? :)