[LeoPanthera]

I have a tiny bash script that picks four random common words from the list of the 10000 most common words on Wikipedia and tries to ping <word>.com for each.

It's quite rare to find an unregistered one.

[qingcharles]

I did this via some sort of bash + WHOIS call in about 1995 with the dictionary file I normally used for passwd cracking. There were a lot available then.