Vietnam, here we come!

tomorrow, I'm heading out to Vietnam with three of my girl friends, Jackie, Grace, and Sangita. we're going to hit Saigon, Hue, Hoi An, Hanoi, and Halong Bay - that's five cities in one week. what can I say? we're ambitious!

the only things on my to-do list so far: explore caves in Halong Bay, eat, take pictures, and eat some more!
anyone with recommendations for cool things to see or do there? let me know!