Cyclos are the slowest and least maneuverable vehicles on Hanoi streets, although they tend to stay along the edges of traffic and are not as vulnerable to higher-speed accidents. Officially, the local economy runs on the dong. All hotels and restaurants accept both currencies, as well as the vast majority of shops. Prices are often denominated in dollars. Credit cards, on the other hand, are not yet widely used in Hanoi.
Checks are unheard of.
ATMs are scarce and should not be relied on for extra cash. When changing money, large bills net a better exchange rate. Hang Gai is part of the 36-streets section of town north of Hoan Kiem Lake. It is on every tourist map, and any taxi driver can find it. For ethnic handicrafts, another shop well worth considering is Craft Link, located on Van Mieu just across the street from the Temple of Literature.