I appreciate my local orchid society for some of the same reasons I appreciate Orchid Board. It's a place to learn, and a place to connect with people with common interest. Although I do have my own alone time caring for my plants, it's very important for me to be able to share my interest and the fruit of my labor with others. My local club really encourages all the members to bring their blooming plants for the show table(s). For me to take the time to go to the meetings, it is a huge motivating factor to know I am going to get to see what others in my area are growing/blooming. And I always pick up a at least a nugget or two of insight from the lectures, some more than others.
I like a lot of the previous suggestions. As was stated already, I would try putting out business cards at local nurseries, florists, feed stores, gardens and anything else remotely plant related. Again I know this was already said, but state on the flyers/business cards that new members get a free orchid! Also, keep posting on craigslist and do make a Facebook fan page and blog page. It's good to have an online presence so people in your area can find you when they do a search, and plus it's free!
Congrats for starting an orchid club and good luck!