Our local CERT makes big use of amateur emcomm. But it's the non-critical stuff: neighborhood liasions to go out and spot things, or volunteers in a truck to relay supply needs at peripheral stations.
It's a parallel line of communications (with a separate set of humans making a judgment of what's important to escalate), which is useful when administrative and decision-making capacity is constrained. And it has different failure modes, which is nice, too.
Even little things: visible volunteer patrols by amateur operators for fireworks laws violations just helped my city tamp down the normal dozens of fires to only two and hastened the firefighting response.
