The town is well-connected to the north and south by bus. The AXA bus line provides quite civilized transport at a reasonable price. There are also cheaper, rickety buses available, as well as the usual minibuses which hold up to 20 people - scary but cheap.
If coming from Mbeya, Tanzania be careful of well established scam artists selling fake bus tickets. One of the scam artists even has an office in the main transit area in Mbeya. He also has professional looking lists of prices, services, etc. He may even use a cell phone to check availability of seats for you. As of September 2008 there were no buses running from Mbeya to Mzuzu or any other town on the Malawi border.
Instead, to get to Mzuzu from Mbeya, take a minibus to the border town of Kyela, Tanzania. Then walk 5 to 10 minutes across the border to the Malawi side. After the border, it's necessary to get to the transit center of a small town called Karonga. There may be minibuses at the border, but they are infrequent. A taxi can be hired for about $15USD. Once in Karonga there will be minibuses headed to Mzuzu.
Swiftair operates scheduled flights from Lilongwe to Mzuzu and karonga on a twin engine, 2 crew beechcraft 1900 (http://www.swiftairmalawi.com)
