Taxis are plentiful and reasonably priced. For the most part, they're a safe means of transportation, though some of the vehicles are a bit past their prime, and some of the drivers more than enthusiastic. You'll find taxis on Viti Levu, Vanua Leu, Ovalau, and Taveuni by bus station depots or major intersections. Taxis are reasonably priced—$2.50 will take you almost anywhere you need to go. Drivers are usually Indo-Fijian, friendly, and English-speaking. They're also keen to cut deals: you can save money on other trips if you allow them to pick up extra passengers and you can negotiate a daily rate (think personal chauffer service).
Make certain you negotiate a price before starting out, or make certain the meter is on—many drivers won't use it if they don't have to. Also, if you're traveling to a remote area, ask whether it's a return taxi so you aren't stranded.