It's been done before. You should check out the TV series, "How to Start your Own Country" by Danny Wallace who covers all the bases and lets you
know just what is required for independance!
You should also check out his nations website
www.citizensrequired.com...
Declaring self-independance though will likely result in an international blacklisting. Ever hear of Abkhazia, Transdniester, or South Ossetia? If
you haven't it's because the international community refuses to acknowledge their existence as independant nations. And if you want your new nation
to join the UN you'll need a two thirds majority vote from all member states. But even if you get that the most powerful nations, i.e The US, China,
Russia or the UK can still veto the application. Anyway, good look mate, I'm behind you if you decide to make a real go of it!
[edit on 24-6-2010 by Random_Hero10]