1- Use your signature to promote alternative forums. Think of it as a bumpersticker.
2- Put your own email address there too so people can get you if things crash. Set up an expendable one at Yahoo or Hotmail so you can ditch it if spammers strike.
3- You might want to visit
http://www.forums4free.co.uk/forums/?mforum=neurotalk
Neurotalk is an experimental forum that I set up in a half-hour on forums4free. You will find that the interface is almost identical to BT. If needed, anyone can set up a BT-like environment. The trick is getting people to come.
Prepare in advance. -Rick