Yeah actually if you wanna enjoy (enjoy?) Adsense for domain but you don't have unused domain, you can use free domain registrar to enjoy it easily, so where's the free domain registrar? Yap you can signup co.cc but there are new free (sub)domain registrar that offering CNAME and A record for your free domain, that's co.tv.
Yeah (again) let's try co.tv and enjoy more "Adsense for domain" revenue. I'd enjoy it, but I got nothing for that haha..