DataCatalogs.org aims to be the most comprehensive list of open data
catalogs in the world. It is curated by a group of leading open data
experts from around the world - including representatives from local,
regional and national governments, international organisations such as
the World Bank, and numerous NGOs.
The alpha version of DataCatalogs.org was launched at OKCon 2011 in
Berlin. We have plenty of useful improvements and features in the
pipeline, which will be launched over the coming months.
More:
http://datacatalogs.org/