There are airports in Palu (for Lake Poso and the central highlands), and Luwuk (for the Togian Islands, Morowhali), with a reasonable amount of domestic departues to Manado and Makassar.
From the south: Buses leave Rantepao in Tana Toraja everyday around 09.00 (delays can be common), and stops at Tentena, Poso and Palu. It should be noted that the road is in a bad condition, with potholes being quite common . Therefore heavy delays can be expected. It can be recommended to try to get a seat on the more comfortable executive bus for this reason.
From the north: An overland busroute goes to Manado by Toli-Toli and Gorontalo, this is not very used by tourists though, as the Togian Islands is omitted on this route.
Small ferries arrives in Ampana from Wakai, the "capital" of the Togian Islands everyday apart from Sunday and Thursday. The 5 hour trip is not very friendly towards people prone to seasickness, but the scenery is very nice.
As of 2006, ethnic violence between Muslims and Christians in the central towns of Palu and Poso continues to simmer. Tourists are not targeted, but there are very few visitors in the area anyway and the police and military presence is very heavy.
However, as of 2011 the situation seems to be much quieter and some tourists have returned. Caution can still be recommended, especially in Poso where some locals might still make you feel like an unwelcome intruder.