We love the space and rocket center in Huntsville! It is reciprocal with some childrens museums. Also, if you're ever in Pensacola, the Navy air museum is really great and it is free. If you go at the right time you can watch the Blue Angels fly in practice. We've done that a couple of times and my kids love it!
The aquariums in Chattanooga and Gatlinburg, TN are also really nice. Chattanooga is just a fun little city really with lots to do. I haven't been to the aquarium in Atlanta but I hear it is fantastic. There is also tons of stuff to do there.
Sounds like you are doing some really neat stuff!
