Given that virtually everyone there was a pretty driven person in terms of their careers and businesses, the talk would be a mix of "getting to know each other" and sharing ideas. I learned countless things at these meetings, both about the people who were trying to build businesses as well as many ideas for how to improve my own business.
I made a few close friends. I built up a lot of connections in my own community. I was able to brainstorm countless ideas for my own business. Best of all, I had a lot of fun, too.
Such a "club" is an invaluable use of your time. In fact, it's worth your time to get the ball rolling on such an event. Here's exactly how to do it.
First, identify a good spot for the first such meeting. Pick a spot where you feel comfortable and that many small businesspeople in your community would also feel comfortable. A nice local restaurant (but not the most upscale place in town) that serves appetizers and beverages is a perfect place for this type of thing.
You should also select a time and a date for this first meeting. Choose a late afternoon time that's least likely to interfere with business and also interfere with family time. I recommend a period from about 4 PM to abut 6:30 PM, but your local business climate might favor a different time. Make the period reasonably long to easily handle various schedules.
Once you've decided on this, get the word out. Directly contact any small businesspeople you know in your own community and don't be afraid to beat the pavement to meet ones you don't know well. Make sure to have a flyer with you that states the basic information and make sure that they're aware that this is informal, just to get to know each other and share ideas.
Make an effort, on the day of the event, to be there the full time. While there, collect the business cards of attendees and afterwards, make an email list for all of these people so you can update them about future events. Don't worry about having topics - if you don't know what to talk about, interview. Ask the people there questions about their business and what they're up to.
With any luck, these meetings will turn into something invaluable and business-building, not only for you, but for all of the attendees.