A couple of years back there was a website I use that switched to usernames as sub domains and I managed to break it by using "webmail" as a username, another user took "ns1" and "ns2" and now my first port of call on sites like this always checking out "webmail", "ns1" and "ns2". So childish but good harmless fun.

I see login.neocities.org is taken as well.

login.neocities.org payment.neocities.org