Here's a social system designed to manage your reputation backtrail. Unlike Klout, Trustcloud evaluates your presence on a number of different social systems. It takes into account your longevity online and your willingness to interact and contribute. You can earn 'badges' based on a number of factors. You can also rate the trustworthiness of folks you know on Trustcloud.
This is all tied to the concept of collaborative consumption. Investigate this if it tickles your interest. ~ Dennis