iPhone game score

Since apple seems to be touting the iPhone/iPod touch platform as a "gaming console" of sorts, I thought it might be cool to implement a sort of scoring system to the different games. While it would be a voluntary addition to games, I think the ability to track your "progress" through games may be interesting. The nice thing is, accounts are already in place and would only need a minute ammendment to carry a game score of sorts. Post your thoughts.