I would agree, get to know some in your area and also if you have a bug out location they are going to, this way they can make contact when they arrive and a message could be relayed to you. One thing to keep in mind with ham's, when a big event happens in an area they tend to be tied up helping out the local L.E. people, at least in my area so getting a message may take some time, I know that would be enough to drive a person nuts wondering what was going on with the rest of the family.
Depending on the situation, lets say it was more localized but still required a relocation quickly a board like this one would serve well, a member could be contacted and a PM or even a post made that things are A OK. Remember even in a S.H.T.F. situation I don't see the entire country coming to a stand still, take 9/11 for instance, trying to get a land line or cell call into or out of NYC was next to impossible, I had people working there, took several hours to get a call through to find out they were OK and on the move, as big of an event as that was the rest of the country still had stable communications.
With that said a trip to a local library in the bug out location may be something to plan for as they typically have Internet access available, or even hotels have computer stations set up, a quick post on a site to say hey were on the move all is well, at least it puts your mind at ease