Other, better BB's exist, it is sure, but would they lead to a better Interact?
Consider for a moment that Interact works very well as a community. And maybe that is due in part to the way the Interact board works. In that some of it's limitations may be features.
Maybe we should think about what makes it work before changing it.
As in maybe 'If it ain't broke, then fixing it may break it.' Aka 'I fixed it till it broke.'
I submit that one of the things that make Interact work is that there is only one conversation. One board, one topic, one moderator. Multiple topics or private message tools might break up the yeasty nature of Interact and let it become fragmented or cliquish.
Also having to scan through a heap of messages to find the thread that you are intersested in, rather than have the e-mail notification point you right to it, might mean that folks are more tempted to join in other threads, thus broadining the conversation.
On the other hand spell checking is nice. So would mo'better editing tools.
Just a thought.