There are lots of things that happen at the convention.  Lots of the very best speakers on cichlids in the world,  the largest all cichlid show in the U.S., tons of vendors selling all kinds of fish and supplies, a banquet dinner, and other general frivolity, antics, and socializing with other cichlidiots!  It's a very worthwhile event.  This will be my third one but the first where I have been part of the host club and I am excited!
Andy

I've been to a few conventions now, and love them.
 
Tons of fish for sale (cichlids of course, including angels and discus, but also catfish.. lots of pleco species) and some live plants as well.
 
There will be big rental rooms where you can rent a tank to either sell fish out of, or to keep fish that you buy in until you are ready to go home (for those travelling).  Vendors will be selling everything from decor to books to food.  Generally some very good raffles of tanks.  Many people will also be setting up tanks in their rooms, and selling out of their rooms.
 
You can usually find lots of species you won't see locally.
 
Lots of speakers, on various subjects.  Silent and live auctions, but try to prepare yourself for the Babes In The Cichlid Hobby auction, their acronym should give you an idea of the craziness that will be going on, as well as the bottle of tequila that may be making its way around the room (the "normal" auction on the last day is generally more what you'd expect, hehe).  Even a photo contest.
 
One of my favorite parts of the convention is always the tours.. In Chicago, we went to the Shedd, in Atlanta, the new Georgia Aquarium (IMO, doesn't even come close to comparing to the Shedd).  Not always fish-related either.  I'm really looking forward to the local ones here too, even though I am from the area.

Many!  There are advantages to being an MAS member and volunteering to work the convention.  But if you are not an MAS member we certainly will not turn you away...  

Quote from dustyandtara on 04/23/10 at 10:10am:

 
There is a huge cichlid show (400-500 fish on average), vendors selling aquarium goods, rental room (tanks to rent to hold fish and sell fish out of), and aquarium set-up to bid on all open to the public free of charge.  And there are also two auctions-Saturday night the B.A.B.E.S auction of donated fish (many are rare fish) and Sunday is the BIG auction.  Both are open to the public.
 
There are also a number of well know speakers (and a few lesser known like myself) scheduelled throughout the weekend starting Thrusday and ending Saturday.  Registered attendees only.
 
Friday night-brat fry-pay event
 
Saturday night-Banquet and awards-pay event
 
Local tours Thursday and Friday-pay event incluiding transportation and some other things
 
Check out http://www.aca2010.com/ for a much more complete list of everything and for updates.
 
Jeff

correct

You do not have to be an ACA member or even pay anything to go to the vendor rooms or auction.  You only need to register if you are wishing to attend the speakers.

I had never been at a fish convention before (but will be),  a little confuse here, my question is, is there gonna be a fish auction or swap every night/day of the convention or is it set up for certain night/day only?  and for the speaker, are they speaking to a seperate crowd away from the auction room or are they speaking before/after the auction?