There is a 24-hour car ferry between Jorf, on the mainland, and Ajim on the island of Jerba (15 minutes, 800 mills per car). There are ferries from Sfax to the Kerkennah Islands, but not many reasons to go there.
Hitching is possible down the coast to the Libyan border and as far south as Tozeur, although you may be expected to pay the bus fare equivalent. Hitching in the north is easier away from the main tourist areas, and you’ll seldom be expected to pay.
Although many people do hitch, bear in mind that it is not an entirely safe means of transport. Women should never hitch alone, and even in pairs it will be much more hassle than it could possibly be worth, and not necessarily safer.
The national bus company, Société Nationale du Transport Interurban (SNTRI), has daily air-conditioned buses between Tunis and most towns. Advance booking is advisable, especially in summer and around important holidays. Sample one-way fares from Tunis include Sousse (US$6) and Jerba (from US$18 to US$20).
Local buses are run by regional companies and go to all but the most remote villages.
Louages are large cars or minibuses. They are always white with a red stripe across the front and along the side, and they ply the same routes as the buses. They are usually cheaper and faster than buses and are quite safe. They leave when full – you rarely have to wait long for departure. Prepare to be cramped inside and avoid the back seat and the middle seat in the front (seriously lacking in head and leg room respectively).
All towns have metered private yellow taxis. These can either be hired privately or they operate on a collective basis – they collect four passengers for different destinations. If you take a shared taxi, your fare will be much cheaper.
Tuninter operates internal flights from Tunis to/from Jerba, Sfax and Tozeur. Tuninter tickets can be bought from its parent Tunis Air (71-330 100; www.tunisair.com; 48 Ave Habib Bourgiba, Tunis), or from any travel agent. Tuninter (701 717) also has a special reservations service.