There is a EMS, Fire, and ESDA related forum @ www.landofzoz.com . Its mostly central IL people, and has alot about scanning. Theres some good fire/ems stuff though. Its worth a look.
Well, here's the boards I'm active in (besides this one):
Firefighters Forum - small group, very friendly, first forum I got involved with.
American-Firefighter.com Forum - also a relatively small group, seems to have a lot of younger posters (explorers and such) as well as quite a few active FFs.
And of course, Firehouse.
I'm also active in the Code 3 Collectibles Bulletin Board, which is focused on Code 3's line of 1/64 scale fire apparatus, but has some general FD discussion as well.
I'm SafetyPro on all of them, FYI.
There's a few others out there that I've looked at but not found worth my time to get involved with.