The best way to get around the Big Island (since it is, ahem, quite big!) is to rent a car instead of relying on public bus service, especially if you plan on taking day trips. There may also be tour options available, especially if you are staying in Kona, which tends to be a little more tourist-oriented than the laid back town of Hilo. Some will even opt to fly in to one airport and out the other, in order to maximize their time on the island and to avoid back tracking on the long drive between the major towns.
