Laura and Renato have created a superb, back to basics beach lodge which also appeases my eco-tourism yearnings. Their description is honest and accurate, so if you want a simple no-frills beach holiday right on a paradise beach, this is the perfect place.
The rooms are right on the beach - we didn't need to wear shoes, except for leaving the lodge, all week. The rooms are beautifully rustic and traditional, with mosquito nets (rooms were sprayed in the evening too). Nothing in Africa is built to perfection, but that is the charm. Very comfortable beds, furniture mostly made out of rough wood (this is the 'Twisted' Palms). Bathroom basic and functional.
The restaurant serves simple but excellent and tasty food, usually fresh from the locals who fish directly off the beach. The Zanzibarians are lovely people, very friendly, but poor in comparison to the lodgers, so tip!
The lodge is nominally guarded by some Maasai in traditional dress, but in reality there is little risk. The Maasai usually end up playing football on the beach in the evening, in lieu of anything much better to do.
Go to see the Colobus monkeys in the Jozani forest - they are fantastic. The snorkeling and SCUBA is excellent too, but I would go on an organised trip to a lagoon, where the waters are deep around the reef and go at a time of day so that the tide doesn't create a strong current.
Don't go to an up-market hotel, Twisted Palms is far, far better and you will feel more in touch with Zanzibar :-)