There is great golf nearby.:
The 2 golf courses of Kona Country Club are about a ten minute drive away. There are many other great golf courses in the area. Waikoloa has 3 beautiful courses about 25 miles north of the Kona airport; Waikoloa Village, Kings and Beach courses. Big Island C.C. has an interesting upcountry course with an island green. Waimea C.C. is another upcountry course, I've haven't played it yet though.
Courses not to miss also at Mauna Kea and the Mauna Lani North and South courses.
The Volcano is worth the drive.:
Past the southern tip of the island Kilauea volcano at Volcanoes Nat'l park is well worth the trip. It has been actively erupting for years, and can lava can be seen flowing into the ocean for those feeling adventurous. It is a bit of a hike through the lava fields. Beautiful tropical plants growing everywhere wild orchids growing along side the road, it is truly the Hawaii you pictured in your mind when you first heard the word Hawaii.
Other Activities:
great snorkeling beach 5 minutes away