Current business plan (apparently only slightly facetious):

1. Get everybody on Facebook 2. Create a huge map detailing how everybody relates to everybody else. 3. ???? 4. Profit

I always figured that there were smarter people than me working on step 3, but maybe there weren't.

Maps of the non-social kind are useful because they can be bought and used to get to places you've never been to. Maps of the social kind are apparently useless because everybody wants their privacy and you're basically left with a map telling you where you are and what's within two steps walking distance.