I just went to one locally so I can tell you about me experience, hopefully that will help you a little. The frag swap was from noon to 4. We got there around 1:30, it was hectic as heck to try and find people whom I had reserved frags from on fragswapper.com. After about 15 minutes of walking around the place I got the hang of it and it was fun finding those people. It will be crowded, this place was kind of small and it had more than 300 people standing around looking and buying frags. When you go make sure you bring a cooler so you can take your frags home, a towel also just in case you get wet. The people selling frags usually have bags or plastic containers that they put the frags into, similar to your LFS
bagging stuff up that you buy. Here is one tip for you, don't reserve too many frags on fragswapper or wherever your local frag swap has stuff up. Wait until towards the end of the frag, and haggle with the sellers. I got a frogspawn and a torch coral that was listed at $15 a piece at the beginning of the swap for $10 for both of them towards the end. Make sure you bring at least $100 in small denominations(5,10). Get the frags that you REALLY want early, other than that wait till towards the end to buy your frag. Hope this help, I had a lot of fun and will be going again in the fall.