Nai/Fiji: What to see in a few hours...

Hey! I arrive in Nadi tomorrow in a week in the morning. Before hopping on the ferry the next day, I want to see something of the island itself. Any suggestions what to do outside of Nadi? Do you know how much it is to hire a taxi for a few hours and what I would be able to see in 4-6 hours? Ideally, I could organize this at the Airport after arriving there...

A taxi from the airport to Lautoka is about F$30 each way, alternatively take a local bus for about F$5. Allow an hour each way.
Go to the market in Lautoka and have a wander around town. You will also see some countryside and local towns along the way.

Cheers,
Peter