Perhaps surprisingly, the most interesting incentives have been developed in an emerging economy: South Africa. The Discovery group, based in Johannesburg, has crafted a programme called Vitality that applies the “air miles” model to health care. You earn points by exercising, buying healthy food or hitting certain targets. You rise through various levels, from blue to gold, as you accumulate points (rewards are adjusted to your starting level of fitness to give everybody a chance of making progress). And you are given a mixture of short- and long-term rewards ranging from reduced premiums to exotic holidays... This model has taken Discovery from “one man and a desk” in 1992 to become South Africa’s largest health insurer, with 5,000 employees.
That's from the Economist. One disagreement: I don't find it surprising that some of the most innovative models are coming out of an emerging economy -- in fact I imagine that if you're looking for innovative social ventures and policies, BRICS are the countries to keep an eye on.