While there are countless incentives to better yourself -- sclerotic arteries, a cellmate named Bunny -- none can force your hand like your own deplorable miserliness. To harness the power of your cheap, try Stickk.com.
Founded by two Yale profs and a Yale MBA dropout, NYC-based Stickk forces you to keep your resolutions via "commitment contracts": legally binding promises to follow through, or else forfeit funds to a third party (your choice of Friend, Foe, Favorite Charity, or Most Hated Charity). First, set a goal (Stop Smoking, Lose Weight, Exercise Regularly, Stop Lying to Self), next define the value of the pledge from a $1 min to a no-limits max, then set the length of commitment -- up to 52 weeks, after which you might consider hiring a Jewish mother. As for reporting performance, there's the honor system (unreliable), or you can appoint a "referee", who'll relay your status back to Stickk -- potentially triggering the monetary transfers you agreed to back when you were merely fat, rather than a fat failure.
In all disputes, your referee has final say, but if he mysteriously disappears, your terms will revert to the honor system -- thus totally undermining your efforts to stop murdering helpful friends.