1.) sign up for a free account at cloudflare.com
2.) type in any domain (you don't need to own it)
3.) click "add domain" and wait about a min
That's it!
I know you can use the command 'dig example.com axfr', but my experience is most domains don't allow zone transfers so this command will fail.
Would be interested in learning how cloudflare is able to list this information..