I don't currently have a micronation, though I do hold dual citizenship in Beerhaven and the USA. (@TheProfessor - when my brother, a professional graphic artist, saw Beerhaven's arms, he said, "I hope somebody paid you for that." To which I answered, "Oh yes, I got an honorary citizenship in this country of his.
)
Back in my days as a high school actor, I did rule a nation called, if memory serves, the "Microrepublic Slash Dictatorship of Ben", which formed in response to my friend Adam's annexation of an adjacent dressing room. The advantage of my micronation was that it was actually a closet barely big enough for one, so I didn't have the territorial disputes that plagued the Republic (or Kingdom, or whateveritwas) of Adam. The small size also made the MSDB ideal, when I had a steady girlfriend, for the sorts of activities done by teenagers rich in hormones but possessing neither prudence nor foresight.
I've got a fictional country with a website, but it's not really a micronation because I'm not its ruler or a citizen. It's part of the Ill Bethisad project:
http://sites.google.com/site/ibhenua/
Along the same lines, I'm also a fan of a non-micronation called Fyksland and may as well post it to this thread:
http://www.vaijska.net/en/index.php