here is the gist of it :

• use the firefox-add-on : https://addons.mozilla.org/en-US/firefox/addon/b-dns/

• visit the search engine: http://grep.geek/

• use the openNIC proxy : http://proxy.opennic.org/

• need a faster wiki than this? use the fossil wiki: t.b.a.

• which TLD has the most subdomains? http://report.opennic.org/ see TLD info from menu

• finally: quickly give your BIND named a live test : http://report.opennicproject.org/t2log