At the 2007 Greensboro NC conference I think we charged them about $10 or 15 for field trips only.
Several teachers and other curious locals joined us this way.
Might want to get some kinda poster up in local fish shops, bait/tackle shops, libraries in the Roanoke area.
I'll get the website updated, but we'll make it the same as the daytime-only registration, $15.
I've sent a flyer to local fish shops and I've been working with the visitors bureau. I'll send them an email asking where else I can send flyers.