I went with a mixed group of family and friends for two of the three days of Stellar Fest a small sci-fi convention in Atlanta, GA this past weekend. We did some trade with their merchants (bought pretty coats), saw a few interesting panels (Space Archaeology!), and generally had a great time. The con staff were very helpful and there were many signs and maps posted to help us find everything.
For the Federation and T'HY'LA: I was able to meet a few Trek fans and gave out some of the Federation/T'HY'LA cards. I made friendly diplomatic contact with Starfleet, another Trek fan organization who had a table there. They were very welcoming and freely admitted that both orgs are trying to the same things and many people are members of both and they invited me to join.