Interesting question. I wonder if you could get into this list (without nefarious purpose) if you provided some major hosting service? Eg: I see k12-schools in the US are on that list, it would make sense to allow someone providing shared hosting to get on the list (to avoid users setting cross-domain cookies). Eg: appspot.com and blogspot.* is on the list[1].
More information:
http://publicsuffix.org/submit/ (and the rest of the site, obviously)
Or, you could buy one regular domain and then ask to be put on the public suffix list. I'm guessing that would have the same effect for less money.