Glassboard Premium is the amped up version of Glassboard, which I happen to love.
Recently I used it at WWDC to organize a trip to a local climbing gym with a handful of folks. The discussion started out on Twitter, but then I quickly moved it to Glassboard once it was obvious the conversation was too hard to follow. Glassboard works great for situations like this. We also use it up in Seattle for the local Xcoder's group. Glassboard ins't a mailing list, and it's certainly not Twitter or Facebook. But it's without a doubt something awesome.
So if you're tired of "social" apps where you are the product and not the customer, Glassboard is what you need to solve that problem.