[OT] Being a speaker at a convention

I've been getting a lot of suggestions and requests from people that I should attend conventions, but not as a fan, but as a speaker. They think that I should go and be on one of the panels of people that speak about Power Rangers and Super Sentai, one person suggesting Power Morphincon. I've thought about it, but with my schedule and budget, that is not possible at this moment. However, I kinda like the idea. The ability to actually interact with Ranger/Sentai fans would be great, and I'd love to provide my input to large crowds. (Plus dressing up is always great too!) I guess what I am wondering is; if I did decide to be a speaker at a con, how do you go about it? I admit the only con I have ever been to was a Star Trek con in Indianapolis in 1998. It was a strange experience, but not for the reasons you may think. Anyway, if I do decide to do the con circuit to promote The Onyx Tavern and provide my input, how would I go about doing it? Anyone here know the process? I've looked at a couple of con websites and they don't provide much information beyond who is there and how to get tickets, nothing about how to be a guest or a speaker on panels. So if anyone has any information to pass along or can point me in the right direction, that would be great. Thanks guys!