Portoferraio's old town is small enough to walk in any direction — from harbour to fort, fort to fort, fort to beach — within twenty minutes. The streets are stepped and steep; sensible shoes help. The wider commune (Villa San Martino, Bagnaia, Magazzini) is best reached by car or by the ATL local buses that radiate out from the bus station at the western end of the harbour.
For exploring the rest of Elba, renting a car is the obvious choice — the island has good roads and the major beaches are 15 to 30 minutes from Portoferraio. Rental agencies cluster on the harbour and offer summer rates that drop sharply outside peak season. Cheaper alternatives are scooter rental (popular and practical in a town this size) and the ATL bus network that connects Portoferraio to most of the major beaches and towns at modest fares.
Bike rental is increasingly available; the coast road to Enfola is the obvious flat ride, but the interior of the island climbs steeply. Taxi ranks are on the harbour and at the bus station; agree the price beforehand. Boat hire for trips around the coast can be arranged at the harbour.