Hope_Fowl - 9:45 pm on Jun 13, 2010 (gmt 0)
It's not hard to find that there are two types of existing reverse lookup services: Directory search sites, and sites which collect people's opinions about calling numbers. As others have pointed out, the existence of similar sites is not a reason to not try to do better (see Yahoo, Altavista, Google, Bing).
Personally, I hope that this guy comes up with a twist which is so much better than all the others that the others go away. Or at least that they stop cluttering the search results.