Rarotonga is a cute little town. We just returned from several weeks in the S. Pacific and stopped here. There are lots of souvenir stores, and if you are interested in black pearls, they are quite a bit cheaper than in Papeete. However, I understand you have to choose carefully as quality can be iffy. We only spent a few hours so can't comment re excursions, but there is a tourist office on the main street who could probably advise you.
