Auto discovery of new sites

I know there is a web site called [BTDigg](https://en.wikipedia.org/wiki/BTDigg) that is a search engine based on data from DHT. I wonder if a similar search engine could be devised for ZeroNet. I know there is a namecoin directory, but it seems limited to namecoin domains only. There must be sites that exist we are not finding yet that exist on the DHT network.