One problem I face on a local level is the availability of Facebook on the county network. Many times govt. IT departments will not allow access to social networking sites due to the potential for abuse, i.e. time wasting.
"Linked In" seems to be an exception due to it's business like status. (Don't tell the network admins. that's it's really a social network, please...)
Twitter still works, perhaps because of the short message limitation
Are you working in other parts of the new media also?
Have you considered the "NING" community? It seems to be another alternative for specific groups or communities.