Nice. I run or belong to about four Threadable lists at this point, and it's great, but on a couple of them I've really missed not having access controls.
Let us know how they work out for you! We tried to anticipate a lot of the main access control points, but there's probably things we've missed.
I'm really happy to see Threadable adding access control options!
WOW. This is brilliant! This is going to kill Google Groups.