I don't know if there is anything near you but a good place that I have found that lists such things is at kingsnake.com. There might be other places out there but if you follow this link http://www.kingsnake.com/events.html you might be able to find something near you. Good luck! They are so fun!
The next one that I'm aware of - that's within our general area - is September 26-27, 2009 at the Sacramento Convention Center. Hopefully, we'll see ya there
There is the Reptile Expo in San Jose on Aug. 8-9 at the San Jose Fair Grounds. I wne tlast year and they had some really good deals and great Reptiles i am fasho going again this year!