As you know, you're not a country without a flag.
Always a great way to think about sovereignty, tax policy, and the social contract between individuals and government, Sealand became a preferred destination for "a crew of armed cypherpunks, amped-up networking geeks, and libertarian swashbucklers is seceding from the world to pursue a revolutionary idea: an offshore, fat-pipe data haven that answers to nobody" but it seems perhaps the dream has died. The best part of the story is how Sealand nationalized its entire computer industry, by forcing a buyout and seizing control of HavenCo, a data hosting service company. It seems Sealand's royal family felt that allowing HavenCo to operate as a data haven made things difficult for Sealand's relationship with Britain. So many interesting issues of international law, diplomacy, and policy going on in this--enough to write a law review article it seems!