I've been finding some pretty good deals on flights if I fly into Hong Kong first...Would make sense to start at the top of vietnam and work my way down into the rest of SEA....does anyone know a cheap, efficient, way to get from HK to Hanoi?

BnA member AsiaExpert has a lot of great info about Hong Kong in his posts. Might be worth a PM to him to see if his knowledge extends to leaving HK as well.