The two halves of Luang Namtha can be individually easily covered on foot, but you'll want to hop on a tuk-tuk 10000 kip/person for going to the airport, the bus station or crossing over between the two.
You can get a good map of the city at K.N.T internet for 3,000 kip and some guesthouse will have a copy of it for free for guests.
You can rent really good mountain-bikes at a shop along the main road for 15,000 kip per day or 3,000 kip per hour.
Small semi-auto motorbikes eg. Honda Dream copies are now readily available esp. across from the night market or at Zuela Guesthouse and should cost about 30,000-50,000 Kip per day including helmets and a free map. With a motorbike, you can travel around to visit the many villages around and in Luang Namtha and also see the scenic countryside eg. closer to Muang Nalae, Vieng Phouka or Muang Sing.
