What domain name should I use for my extension's fully qualified name?
You can pick anything you want as the domain name. I sense that these answers could get hilarious. Some suggestions from me (others please add your own):


lolcats.com
shouldiblamecaching.com
dotcom.com
3.141592653589793238462643383279502884197169399375105820974944592.com
thelongestdomainnameintheworldandthensomeandthensomemoreandmore.com


But of those, lolcats.com says "extension developer" to me the most: