Here is a nice story from Alexander about why time-based reputation is a very good idea.
Actually this idea just pop in after I have been in Italy for so many years. I saw all the initiative, either from churches, Vatican, NGO, etc. but still they could not send the homeless away. So there is something wrong. Most of us are quite generous and give our excess wealth through different channels, institution, non-profit and others. But nobody has tried it by themselves.