http://www.uniset.ca/naty/BNA1948.htm
The British Nationality Act 1948
Which should be read in conjunction with this from the UK Border Agency.
http://www.bia.homeoffice.gov.uk/sitecontent/documents/policyandlaw/nationalityinstructions/nisec2gensec/legitimacy?view=Binary
El gato has beem made aware of this and continues to post Obama was a UK citizen.
He was not...unless you find a valid marriage in Kenya or was born in Kenya