Perhaps this is not the worst idea for fighting crime, but it is surely not the best idea, either.
We need more cops on the beat, more community policing and increased contact with neighbors. And we need more tax revenues to pay more cops to do that. Cameras only become an excuse to shift financial resources away from community policing and to cut more taxes that would otherwise be used to secure our neighborhoods.
03/14/2005 Update: Here's a BBC story, via the Nashville Scene's Bruce Barry on Pith in the Wind, that indicates that the usefulness of video surveillance as a crime deterrent is "overstated."