Well, I was going to write up a bit of a bash on O Scale Central, but I've had a look around at their website and decided there's really no reason to do so. A) it's an effort to support an advocate for O scale, which is certainly a challenge and often a thankless job. B) it's not the O Scale Central v1.0, which as Jordan suggests, featured a very limited amount of content and usefulness. And C), the original question really only pertains to the membership aspect.
Regarding membership, I'm afraid I don't have much to add, except that I can't find anything on the website that explains to me
why I should want to become a member, or what benefits I might receive by doing so. I think that's a fundamental failure, but I'm sure it could be addressed by
sending an email to Joe Barker, who is the OSC membership manager. But I don't see anything tangible that the $24 membership fee yields, like an O scale oriented quarterly publication or access to exclusive content or product.
Thinking about what I see on the website and the presence that I see from OSC at various shows, I think the $24 membership is probably mostly a way to support the organization in it's outreach efforts, by helping to defray the costs of promotion. I'm guessing that the money goes toward costs such as website hosting, travel to and from shows, and booth/table rental and the signage/content associated with it.
Whether it's worthwhile to join will be a personal decision, but there has to be something to show for doing (and paying for) it. It either has to be something tangible like a quarterly gazette, or it has to be something bigger picture like increasing participation in O scale to maintain a critical mass or make it more appealing to manufacturers. Ironically, I almost certainly would be more willing to join in pursuit of the latter rather than the former, so I may need to explore a membership despite its limited immediate value to me.
I'll follow up with a bit more later, not so much about OSC but rather to learn what you are interested in with regard to US outline O scale. I certainly don't know everything, but I'm decently knowledgeable and I'm happy to answer questions.
Hope that helps,
Jim