the poster shops are in the old quarter one was Hang Bac street.
That sounds like where I'm thinking. In one section of the old quarter there was a modern art university... there were tons of galleries, furniture stores, etc... that had really really cool, yet reasonably priced pieces.
If you think Hanoi is bad for crossing the street Saigon is 10x worse. They advise you to close your eyes and walk slowly.
We were in Ho Chi Minh City as well... that is about what I remember! We had a group of 5 people we were traveling with. We would wait for a local to start crossing the street and all walk in step with them to use them as a blocker. It was pretty terrifying at times... but if you panic, you are toast!