In the Bay Area, where we live, for example, I'm a member of yahoo groups for my neighborhood and others nearby, and I'm a member of the Golden Gate Mothers Group, which has an active caregiver search message board with tons of these types of «great - nanny - for - hire» postings. (hintmama.com)
On a parent yahoo group I frequent, one parent lamented «what's with kids on iPhones in restaurants?!» (themotherco.com)
(Note: The trademarked term is LISTSERV) It's a group email list that you join, usually through yahoo groups. (killzoneblog.com)