Tanjung Pinang is small enough that the centre can be explored on foot. For longer distances, taxis, motorcycle taxis (ojek), and minibuses are all cheap -- most trips within town cost under a dollar.
There are no metered taxis, so always agree on a price before getting in. A flat rate of around $3 covers most trips within the town limits, with a few dollars extra for out-of-town destinations. Minibuses and boats generally run on fixed routes with set fares.
For trips to Trikora Beach or the northern resorts, you will need to arrange a taxi or hire a motorbike. Boats to Penyengat Island and other nearby islands leave from the main harbour throughout the day.