The new Pensions Act has made some important changes for those reaching State Pension age after 6 April 2010.
You now need only 30 years of contributions for a full pension, and any shortfall of years gives you a pension as a proportion over a base of 30 years.
Anyone now living overseas but who has previously lived and worked in the UK may be eligible to pay voluntary contributions and receive the UK old age pension at age 65.
Check out further details here:
http://www.thepensionservice.gov.uk/pen ... m/home.asp
(Many thanks to john5655, who originally drew our attention to this on the Canada forum.)