John writes “… I hadn’t noticed, at 25-yard intervals along all roads in populated areas of Montana, huge public-service billboards warning, often in extremely grisly terms, of the dangers of crystal meth.” Which got me to thinking about 25-yard-apart signs, and if I was in charge of a just-say-no-to-drugs campaign the billboards would read like this: Take Crystal meth – You’re a drug slave! For clean, safe kicks Try Burma Shave.