A nice way to tour a city is to rent a cyclo.
Locals pay half that price.
In Hanoi prices are more related to the distance and are a bit more expensive. Lars used to get short cyclo-rides, Saigon . But not always, some drivers refused to go for this price. When riding in a cyclo, make sure that you hold fast to any bags. There are motorcycle drivers that try to grab your bag, even big backpacks.