I'd be interested in something on well, not quite Regexp::Common, but more cookbookish. Proper idioms and algorythms that people often get horridly or subtly (e.g.; bad performance) wrong. Or things that people end up attacking with a toothpick when there was a better way of tackling the problem if they were't afraid of some of the more arcane features of the regexp engine.

. o O ( Where does he get all those wonderful toys? )