For the past few months it's been rather difficult for me to check registration information for .org TLD (Top Level Domains); I do a whois and get back:
The Registry database contains ONLY .COM, .NET, .EDU domains and Registrars.
Then it's fishing around various websites to get the registrar of the particular .org domain I'm interested in. Then via an entry at utopia with cheese [1], I finally learned that Public Internet Registry [2] contains the database in question, and that I can just query whois.pir.org.