I host a site for a superior officer's union, and have worked with them to develop their online community system. Because it says "POLICEMEN" and not "POLICEOFFICERS", it does come across a little more "exclusionary" that it could, but ignoring that... I think if you looked in your area, and interviewed some people from the local precinct, you'd find some very interesting ideas for what the needs of this group might have.
I'll PM you the URL, Ken, but I can tell you, some of the things they really appreciate are, especially as a union, being able to post controlled talk-back about events happening with the local government (politics), and being able to post grievances (when members are hurt or lost in the line of duty). Keeping their members informed and related is no doubt a challenge, and the Internet definitely provides a very effective medium for doing that.
I think any well equiped union has got some money to spend on Internet services that help them keep their members connected. Community building tools and a service model like DomainBusiness might be a very lucrative and beneficial project to pull together. Yahoo Groups and things like are their, but most of those services in an effort to address the largest group, may not do as good a job as a niche offering.
~ Nexus