Check the hotel entertainment schedule for their Gilbertese dancing night. This is a great way to liven up an otherwise quiet stay in Gizo and the singers and dancers put on a splendid show.
Incidentally, I ran into at least a couple people that I'd met in other parts of the Solomons. It would seem that this is the place to be on a Friday night in Gizo!
For a little taste of Pacific Islands culture in the context of a relatively comfortable hotel in Honiara, ask about the dance performances given occasionally at the Solomon Kitano Hotel. There may be a small fee required for non-guests of the hotel, but it's worth it--this may be the last chance you have to enjoy true nightlife before you head out into the "provinces." You'll appreciate it after you've spent some time in the outer islands!