The Ohio Cichlid Association is having their annual OCA Extravganza. It's the world's largest Cichlid and Catfish convention with auctions, lectures, vendors (Ken's Fish will be there!), and clinics.
If you think the NEC was a big convention, the OCA is BIGGER.
I may be going myself.
Book your airfare now. Continental Airlines has a deal for $185 roundtrip, non-stop from Boston to Cleveland. The show is right next to the airport. The flight only takes about an hour and a half.
The hotel hosting the event is offering a good deal on rooms. Go to the OCA site for more info.
For those who are really penny-pinching, Amtrak operates a non-stop train from Boston to Chicago (Cleveland is a stop on the line) for $148 roundtrip ($75 each way). The downside is that it takes 15 hours to get there.