Advertizing was just the first thing that I thought of to defer costs. You're right though - obviously wouldn't work with such a small group.

I realize that using drupal for this group is probably like using a submarine to cross the creek, but I thought that some of its core capabilities (chat, forums, picture sharing, etc) might be useful to the group, and I've been interested in learning a bit more about it. A friend of xtingu's and mine set a copy up for us to play with, but I thought that users might prove good incentive for me to learn more of the ins and outs.

In other words, I know that it's not needed, but it might be fun.