The South Pacific island of Vanuatu has announced that it will accept Bitcoin for its citizenship by investment programme. At current prices (October 2017) investors will need to pay a minimum of 43.6 Bitcoin.
The island state re-launched its CBI programme in March 2017 and it is called the Capital Investment Immigration Plan.
It offers a "honorary citizenship" to foreign investors against one time contribution to a government fund. A single applicant has to contribute $200,000 and a family of four with minor children about $240,000. Potential citizens don't have to live in Vanuatu or even visit the country to qualify.
Vanuatu is a member of the Commonwealth and its citizenship provides investors with visa-free travel to 113 countries, including the UK and Schengen states. It also has no capital gains or income taxes.
Read more on the Government of Vanuatu's website https://vancitizenship.gov.vu/